xref: /openbmc/linux/drivers/net/virtio_net.c (revision a90fa0ad)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* A network driver using virtio.
3  *
4  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
5  */
6 //#define DEBUG
7 #include <linux/netdevice.h>
8 #include <linux/etherdevice.h>
9 #include <linux/ethtool.h>
10 #include <linux/module.h>
11 #include <linux/virtio.h>
12 #include <linux/virtio_net.h>
13 #include <linux/bpf.h>
14 #include <linux/bpf_trace.h>
15 #include <linux/scatterlist.h>
16 #include <linux/if_vlan.h>
17 #include <linux/slab.h>
18 #include <linux/cpu.h>
19 #include <linux/average.h>
20 #include <linux/filter.h>
21 #include <linux/kernel.h>
22 #include <net/route.h>
23 #include <net/xdp.h>
24 #include <net/net_failover.h>
25 
26 static int napi_weight = NAPI_POLL_WEIGHT;
27 module_param(napi_weight, int, 0444);
28 
29 static bool csum = true, gso = true, napi_tx = true;
30 module_param(csum, bool, 0444);
31 module_param(gso, bool, 0444);
32 module_param(napi_tx, bool, 0644);
33 
34 /* FIXME: MTU in config. */
35 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
36 #define GOOD_COPY_LEN	128
37 
38 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
39 
40 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
41 #define VIRTIO_XDP_HEADROOM 256
42 
43 /* Separating two types of XDP xmit */
44 #define VIRTIO_XDP_TX		BIT(0)
45 #define VIRTIO_XDP_REDIR	BIT(1)
46 
47 #define VIRTIO_XDP_FLAG	BIT(0)
48 
49 /* RX packet size EWMA. The average packet size is used to determine the packet
50  * buffer size when refilling RX rings. As the entire RX ring may be refilled
51  * at once, the weight is chosen so that the EWMA will be insensitive to short-
52  * term, transient changes in packet size.
53  */
54 DECLARE_EWMA(pkt_len, 0, 64)
55 
56 #define VIRTNET_DRIVER_VERSION "1.0.0"
57 
58 static const unsigned long guest_offloads[] = {
59 	VIRTIO_NET_F_GUEST_TSO4,
60 	VIRTIO_NET_F_GUEST_TSO6,
61 	VIRTIO_NET_F_GUEST_ECN,
62 	VIRTIO_NET_F_GUEST_UFO,
63 	VIRTIO_NET_F_GUEST_CSUM,
64 	VIRTIO_NET_F_GUEST_USO4,
65 	VIRTIO_NET_F_GUEST_USO6
66 };
67 
68 #define GUEST_OFFLOAD_GRO_HW_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
69 				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
70 				(1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
71 				(1ULL << VIRTIO_NET_F_GUEST_UFO)  | \
72 				(1ULL << VIRTIO_NET_F_GUEST_USO4) | \
73 				(1ULL << VIRTIO_NET_F_GUEST_USO6))
74 
75 struct virtnet_stat_desc {
76 	char desc[ETH_GSTRING_LEN];
77 	size_t offset;
78 };
79 
80 struct virtnet_sq_stats {
81 	struct u64_stats_sync syncp;
82 	u64 packets;
83 	u64 bytes;
84 	u64 xdp_tx;
85 	u64 xdp_tx_drops;
86 	u64 kicks;
87 	u64 tx_timeouts;
88 };
89 
90 struct virtnet_rq_stats {
91 	struct u64_stats_sync syncp;
92 	u64 packets;
93 	u64 bytes;
94 	u64 drops;
95 	u64 xdp_packets;
96 	u64 xdp_tx;
97 	u64 xdp_redirects;
98 	u64 xdp_drops;
99 	u64 kicks;
100 };
101 
102 #define VIRTNET_SQ_STAT(m)	offsetof(struct virtnet_sq_stats, m)
103 #define VIRTNET_RQ_STAT(m)	offsetof(struct virtnet_rq_stats, m)
104 
105 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
106 	{ "packets",		VIRTNET_SQ_STAT(packets) },
107 	{ "bytes",		VIRTNET_SQ_STAT(bytes) },
108 	{ "xdp_tx",		VIRTNET_SQ_STAT(xdp_tx) },
109 	{ "xdp_tx_drops",	VIRTNET_SQ_STAT(xdp_tx_drops) },
110 	{ "kicks",		VIRTNET_SQ_STAT(kicks) },
111 	{ "tx_timeouts",	VIRTNET_SQ_STAT(tx_timeouts) },
112 };
113 
114 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
115 	{ "packets",		VIRTNET_RQ_STAT(packets) },
116 	{ "bytes",		VIRTNET_RQ_STAT(bytes) },
117 	{ "drops",		VIRTNET_RQ_STAT(drops) },
118 	{ "xdp_packets",	VIRTNET_RQ_STAT(xdp_packets) },
119 	{ "xdp_tx",		VIRTNET_RQ_STAT(xdp_tx) },
120 	{ "xdp_redirects",	VIRTNET_RQ_STAT(xdp_redirects) },
121 	{ "xdp_drops",		VIRTNET_RQ_STAT(xdp_drops) },
122 	{ "kicks",		VIRTNET_RQ_STAT(kicks) },
123 };
124 
125 #define VIRTNET_SQ_STATS_LEN	ARRAY_SIZE(virtnet_sq_stats_desc)
126 #define VIRTNET_RQ_STATS_LEN	ARRAY_SIZE(virtnet_rq_stats_desc)
127 
128 /* Internal representation of a send virtqueue */
129 struct send_queue {
130 	/* Virtqueue associated with this send _queue */
131 	struct virtqueue *vq;
132 
133 	/* TX: fragments + linear part + virtio header */
134 	struct scatterlist sg[MAX_SKB_FRAGS + 2];
135 
136 	/* Name of the send queue: output.$index */
137 	char name[40];
138 
139 	struct virtnet_sq_stats stats;
140 
141 	struct napi_struct napi;
142 
143 	/* Record whether sq is in reset state. */
144 	bool reset;
145 };
146 
147 /* Internal representation of a receive virtqueue */
148 struct receive_queue {
149 	/* Virtqueue associated with this receive_queue */
150 	struct virtqueue *vq;
151 
152 	struct napi_struct napi;
153 
154 	struct bpf_prog __rcu *xdp_prog;
155 
156 	struct virtnet_rq_stats stats;
157 
158 	/* Chain pages by the private ptr. */
159 	struct page *pages;
160 
161 	/* Average packet length for mergeable receive buffers. */
162 	struct ewma_pkt_len mrg_avg_pkt_len;
163 
164 	/* Page frag for packet buffer allocation. */
165 	struct page_frag alloc_frag;
166 
167 	/* RX: fragments + linear part + virtio header */
168 	struct scatterlist sg[MAX_SKB_FRAGS + 2];
169 
170 	/* Min single buffer size for mergeable buffers case. */
171 	unsigned int min_buf_len;
172 
173 	/* Name of this receive queue: input.$index */
174 	char name[40];
175 
176 	struct xdp_rxq_info xdp_rxq;
177 };
178 
179 /* This structure can contain rss message with maximum settings for indirection table and keysize
180  * Note, that default structure that describes RSS configuration virtio_net_rss_config
181  * contains same info but can't handle table values.
182  * In any case, structure would be passed to virtio hw through sg_buf split by parts
183  * because table sizes may be differ according to the device configuration.
184  */
185 #define VIRTIO_NET_RSS_MAX_KEY_SIZE     40
186 #define VIRTIO_NET_RSS_MAX_TABLE_LEN    128
187 struct virtio_net_ctrl_rss {
188 	u32 hash_types;
189 	u16 indirection_table_mask;
190 	u16 unclassified_queue;
191 	u16 indirection_table[VIRTIO_NET_RSS_MAX_TABLE_LEN];
192 	u16 max_tx_vq;
193 	u8 hash_key_length;
194 	u8 key[VIRTIO_NET_RSS_MAX_KEY_SIZE];
195 };
196 
197 /* Control VQ buffers: protected by the rtnl lock */
198 struct control_buf {
199 	struct virtio_net_ctrl_hdr hdr;
200 	virtio_net_ctrl_ack status;
201 	struct virtio_net_ctrl_mq mq;
202 	u8 promisc;
203 	u8 allmulti;
204 	__virtio16 vid;
205 	__virtio64 offloads;
206 	struct virtio_net_ctrl_rss rss;
207 };
208 
209 struct virtnet_info {
210 	struct virtio_device *vdev;
211 	struct virtqueue *cvq;
212 	struct net_device *dev;
213 	struct send_queue *sq;
214 	struct receive_queue *rq;
215 	unsigned int status;
216 
217 	/* Max # of queue pairs supported by the device */
218 	u16 max_queue_pairs;
219 
220 	/* # of queue pairs currently used by the driver */
221 	u16 curr_queue_pairs;
222 
223 	/* # of XDP queue pairs currently used by the driver */
224 	u16 xdp_queue_pairs;
225 
226 	/* xdp_queue_pairs may be 0, when xdp is already loaded. So add this. */
227 	bool xdp_enabled;
228 
229 	/* I like... big packets and I cannot lie! */
230 	bool big_packets;
231 
232 	/* number of sg entries allocated for big packets */
233 	unsigned int big_packets_num_skbfrags;
234 
235 	/* Host will merge rx buffers for big packets (shake it! shake it!) */
236 	bool mergeable_rx_bufs;
237 
238 	/* Host supports rss and/or hash report */
239 	bool has_rss;
240 	bool has_rss_hash_report;
241 	u8 rss_key_size;
242 	u16 rss_indir_table_size;
243 	u32 rss_hash_types_supported;
244 	u32 rss_hash_types_saved;
245 
246 	/* Has control virtqueue */
247 	bool has_cvq;
248 
249 	/* Host can handle any s/g split between our header and packet data */
250 	bool any_header_sg;
251 
252 	/* Packet virtio header size */
253 	u8 hdr_len;
254 
255 	/* Work struct for delayed refilling if we run low on memory. */
256 	struct delayed_work refill;
257 
258 	/* Is delayed refill enabled? */
259 	bool refill_enabled;
260 
261 	/* The lock to synchronize the access to refill_enabled */
262 	spinlock_t refill_lock;
263 
264 	/* Work struct for config space updates */
265 	struct work_struct config_work;
266 
267 	/* Does the affinity hint is set for virtqueues? */
268 	bool affinity_hint_set;
269 
270 	/* CPU hotplug instances for online & dead */
271 	struct hlist_node node;
272 	struct hlist_node node_dead;
273 
274 	struct control_buf *ctrl;
275 
276 	/* Ethtool settings */
277 	u8 duplex;
278 	u32 speed;
279 
280 	/* Interrupt coalescing settings */
281 	u32 tx_usecs;
282 	u32 rx_usecs;
283 	u32 tx_max_packets;
284 	u32 rx_max_packets;
285 
286 	unsigned long guest_offloads;
287 	unsigned long guest_offloads_capable;
288 
289 	/* failover when STANDBY feature enabled */
290 	struct failover *failover;
291 };
292 
293 struct padded_vnet_hdr {
294 	struct virtio_net_hdr_v1_hash hdr;
295 	/*
296 	 * hdr is in a separate sg buffer, and data sg buffer shares same page
297 	 * with this header sg. This padding makes next sg 16 byte aligned
298 	 * after the header.
299 	 */
300 	char padding[12];
301 };
302 
303 static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf);
304 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
305 
306 static bool is_xdp_frame(void *ptr)
307 {
308 	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
309 }
310 
311 static void *xdp_to_ptr(struct xdp_frame *ptr)
312 {
313 	return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
314 }
315 
316 static struct xdp_frame *ptr_to_xdp(void *ptr)
317 {
318 	return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
319 }
320 
321 /* Converting between virtqueue no. and kernel tx/rx queue no.
322  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
323  */
324 static int vq2txq(struct virtqueue *vq)
325 {
326 	return (vq->index - 1) / 2;
327 }
328 
329 static int txq2vq(int txq)
330 {
331 	return txq * 2 + 1;
332 }
333 
334 static int vq2rxq(struct virtqueue *vq)
335 {
336 	return vq->index / 2;
337 }
338 
339 static int rxq2vq(int rxq)
340 {
341 	return rxq * 2;
342 }
343 
344 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
345 {
346 	return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
347 }
348 
349 /*
350  * private is used to chain pages for big packets, put the whole
351  * most recent used list in the beginning for reuse
352  */
353 static void give_pages(struct receive_queue *rq, struct page *page)
354 {
355 	struct page *end;
356 
357 	/* Find end of list, sew whole thing into vi->rq.pages. */
358 	for (end = page; end->private; end = (struct page *)end->private);
359 	end->private = (unsigned long)rq->pages;
360 	rq->pages = page;
361 }
362 
363 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
364 {
365 	struct page *p = rq->pages;
366 
367 	if (p) {
368 		rq->pages = (struct page *)p->private;
369 		/* clear private here, it is used to chain pages */
370 		p->private = 0;
371 	} else
372 		p = alloc_page(gfp_mask);
373 	return p;
374 }
375 
376 static void enable_delayed_refill(struct virtnet_info *vi)
377 {
378 	spin_lock_bh(&vi->refill_lock);
379 	vi->refill_enabled = true;
380 	spin_unlock_bh(&vi->refill_lock);
381 }
382 
383 static void disable_delayed_refill(struct virtnet_info *vi)
384 {
385 	spin_lock_bh(&vi->refill_lock);
386 	vi->refill_enabled = false;
387 	spin_unlock_bh(&vi->refill_lock);
388 }
389 
390 static void virtqueue_napi_schedule(struct napi_struct *napi,
391 				    struct virtqueue *vq)
392 {
393 	if (napi_schedule_prep(napi)) {
394 		virtqueue_disable_cb(vq);
395 		__napi_schedule(napi);
396 	}
397 }
398 
399 static void virtqueue_napi_complete(struct napi_struct *napi,
400 				    struct virtqueue *vq, int processed)
401 {
402 	int opaque;
403 
404 	opaque = virtqueue_enable_cb_prepare(vq);
405 	if (napi_complete_done(napi, processed)) {
406 		if (unlikely(virtqueue_poll(vq, opaque)))
407 			virtqueue_napi_schedule(napi, vq);
408 	} else {
409 		virtqueue_disable_cb(vq);
410 	}
411 }
412 
413 static void skb_xmit_done(struct virtqueue *vq)
414 {
415 	struct virtnet_info *vi = vq->vdev->priv;
416 	struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
417 
418 	/* Suppress further interrupts. */
419 	virtqueue_disable_cb(vq);
420 
421 	if (napi->weight)
422 		virtqueue_napi_schedule(napi, vq);
423 	else
424 		/* We were probably waiting for more output buffers. */
425 		netif_wake_subqueue(vi->dev, vq2txq(vq));
426 }
427 
428 #define MRG_CTX_HEADER_SHIFT 22
429 static void *mergeable_len_to_ctx(unsigned int truesize,
430 				  unsigned int headroom)
431 {
432 	return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
433 }
434 
435 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
436 {
437 	return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
438 }
439 
440 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
441 {
442 	return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
443 }
444 
445 /* Called from bottom half context */
446 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
447 				   struct receive_queue *rq,
448 				   struct page *page, unsigned int offset,
449 				   unsigned int len, unsigned int truesize,
450 				   bool hdr_valid, unsigned int metasize,
451 				   unsigned int headroom)
452 {
453 	struct sk_buff *skb;
454 	struct virtio_net_hdr_mrg_rxbuf *hdr;
455 	unsigned int copy, hdr_len, hdr_padded_len;
456 	struct page *page_to_free = NULL;
457 	int tailroom, shinfo_size;
458 	char *p, *hdr_p, *buf;
459 
460 	p = page_address(page) + offset;
461 	hdr_p = p;
462 
463 	hdr_len = vi->hdr_len;
464 	if (vi->mergeable_rx_bufs)
465 		hdr_padded_len = hdr_len;
466 	else
467 		hdr_padded_len = sizeof(struct padded_vnet_hdr);
468 
469 	/* If headroom is not 0, there is an offset between the beginning of the
470 	 * data and the allocated space, otherwise the data and the allocated
471 	 * space are aligned.
472 	 *
473 	 * Buffers with headroom use PAGE_SIZE as alloc size, see
474 	 * add_recvbuf_mergeable() + get_mergeable_buf_len()
475 	 */
476 	truesize = headroom ? PAGE_SIZE : truesize;
477 	tailroom = truesize - headroom;
478 	buf = p - headroom;
479 
480 	len -= hdr_len;
481 	offset += hdr_padded_len;
482 	p += hdr_padded_len;
483 	tailroom -= hdr_padded_len + len;
484 
485 	shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
486 
487 	/* copy small packet so we can reuse these pages */
488 	if (!NET_IP_ALIGN && len > GOOD_COPY_LEN && tailroom >= shinfo_size) {
489 		skb = build_skb(buf, truesize);
490 		if (unlikely(!skb))
491 			return NULL;
492 
493 		skb_reserve(skb, p - buf);
494 		skb_put(skb, len);
495 
496 		page = (struct page *)page->private;
497 		if (page)
498 			give_pages(rq, page);
499 		goto ok;
500 	}
501 
502 	/* copy small packet so we can reuse these pages for small data */
503 	skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
504 	if (unlikely(!skb))
505 		return NULL;
506 
507 	/* Copy all frame if it fits skb->head, otherwise
508 	 * we let virtio_net_hdr_to_skb() and GRO pull headers as needed.
509 	 */
510 	if (len <= skb_tailroom(skb))
511 		copy = len;
512 	else
513 		copy = ETH_HLEN + metasize;
514 	skb_put_data(skb, p, copy);
515 
516 	len -= copy;
517 	offset += copy;
518 
519 	if (vi->mergeable_rx_bufs) {
520 		if (len)
521 			skb_add_rx_frag(skb, 0, page, offset, len, truesize);
522 		else
523 			page_to_free = page;
524 		goto ok;
525 	}
526 
527 	/*
528 	 * Verify that we can indeed put this data into a skb.
529 	 * This is here to handle cases when the device erroneously
530 	 * tries to receive more than is possible. This is usually
531 	 * the case of a broken device.
532 	 */
533 	if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
534 		net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
535 		dev_kfree_skb(skb);
536 		return NULL;
537 	}
538 	BUG_ON(offset >= PAGE_SIZE);
539 	while (len) {
540 		unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
541 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
542 				frag_size, truesize);
543 		len -= frag_size;
544 		page = (struct page *)page->private;
545 		offset = 0;
546 	}
547 
548 	if (page)
549 		give_pages(rq, page);
550 
551 ok:
552 	/* hdr_valid means no XDP, so we can copy the vnet header */
553 	if (hdr_valid) {
554 		hdr = skb_vnet_hdr(skb);
555 		memcpy(hdr, hdr_p, hdr_len);
556 	}
557 	if (page_to_free)
558 		put_page(page_to_free);
559 
560 	if (metasize) {
561 		__skb_pull(skb, metasize);
562 		skb_metadata_set(skb, metasize);
563 	}
564 
565 	return skb;
566 }
567 
568 static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
569 				   struct send_queue *sq,
570 				   struct xdp_frame *xdpf)
571 {
572 	struct virtio_net_hdr_mrg_rxbuf *hdr;
573 	int err;
574 
575 	if (unlikely(xdpf->headroom < vi->hdr_len))
576 		return -EOVERFLOW;
577 
578 	/* Make room for virtqueue hdr (also change xdpf->headroom?) */
579 	xdpf->data -= vi->hdr_len;
580 	/* Zero header and leave csum up to XDP layers */
581 	hdr = xdpf->data;
582 	memset(hdr, 0, vi->hdr_len);
583 	xdpf->len   += vi->hdr_len;
584 
585 	sg_init_one(sq->sg, xdpf->data, xdpf->len);
586 
587 	err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
588 				   GFP_ATOMIC);
589 	if (unlikely(err))
590 		return -ENOSPC; /* Caller handle free/refcnt */
591 
592 	return 0;
593 }
594 
595 /* when vi->curr_queue_pairs > nr_cpu_ids, the txq/sq is only used for xdp tx on
596  * the current cpu, so it does not need to be locked.
597  *
598  * Here we use marco instead of inline functions because we have to deal with
599  * three issues at the same time: 1. the choice of sq. 2. judge and execute the
600  * lock/unlock of txq 3. make sparse happy. It is difficult for two inline
601  * functions to perfectly solve these three problems at the same time.
602  */
603 #define virtnet_xdp_get_sq(vi) ({                                       \
604 	int cpu = smp_processor_id();                                   \
605 	struct netdev_queue *txq;                                       \
606 	typeof(vi) v = (vi);                                            \
607 	unsigned int qp;                                                \
608 									\
609 	if (v->curr_queue_pairs > nr_cpu_ids) {                         \
610 		qp = v->curr_queue_pairs - v->xdp_queue_pairs;          \
611 		qp += cpu;                                              \
612 		txq = netdev_get_tx_queue(v->dev, qp);                  \
613 		__netif_tx_acquire(txq);                                \
614 	} else {                                                        \
615 		qp = cpu % v->curr_queue_pairs;                         \
616 		txq = netdev_get_tx_queue(v->dev, qp);                  \
617 		__netif_tx_lock(txq, cpu);                              \
618 	}                                                               \
619 	v->sq + qp;                                                     \
620 })
621 
622 #define virtnet_xdp_put_sq(vi, q) {                                     \
623 	struct netdev_queue *txq;                                       \
624 	typeof(vi) v = (vi);                                            \
625 									\
626 	txq = netdev_get_tx_queue(v->dev, (q) - v->sq);                 \
627 	if (v->curr_queue_pairs > nr_cpu_ids)                           \
628 		__netif_tx_release(txq);                                \
629 	else                                                            \
630 		__netif_tx_unlock(txq);                                 \
631 }
632 
633 static int virtnet_xdp_xmit(struct net_device *dev,
634 			    int n, struct xdp_frame **frames, u32 flags)
635 {
636 	struct virtnet_info *vi = netdev_priv(dev);
637 	struct receive_queue *rq = vi->rq;
638 	struct bpf_prog *xdp_prog;
639 	struct send_queue *sq;
640 	unsigned int len;
641 	int packets = 0;
642 	int bytes = 0;
643 	int nxmit = 0;
644 	int kicks = 0;
645 	void *ptr;
646 	int ret;
647 	int i;
648 
649 	/* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
650 	 * indicate XDP resources have been successfully allocated.
651 	 */
652 	xdp_prog = rcu_access_pointer(rq->xdp_prog);
653 	if (!xdp_prog)
654 		return -ENXIO;
655 
656 	sq = virtnet_xdp_get_sq(vi);
657 
658 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
659 		ret = -EINVAL;
660 		goto out;
661 	}
662 
663 	/* Free up any pending old buffers before queueing new ones. */
664 	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
665 		if (likely(is_xdp_frame(ptr))) {
666 			struct xdp_frame *frame = ptr_to_xdp(ptr);
667 
668 			bytes += frame->len;
669 			xdp_return_frame(frame);
670 		} else {
671 			struct sk_buff *skb = ptr;
672 
673 			bytes += skb->len;
674 			napi_consume_skb(skb, false);
675 		}
676 		packets++;
677 	}
678 
679 	for (i = 0; i < n; i++) {
680 		struct xdp_frame *xdpf = frames[i];
681 
682 		if (__virtnet_xdp_xmit_one(vi, sq, xdpf))
683 			break;
684 		nxmit++;
685 	}
686 	ret = nxmit;
687 
688 	if (flags & XDP_XMIT_FLUSH) {
689 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
690 			kicks = 1;
691 	}
692 out:
693 	u64_stats_update_begin(&sq->stats.syncp);
694 	sq->stats.bytes += bytes;
695 	sq->stats.packets += packets;
696 	sq->stats.xdp_tx += n;
697 	sq->stats.xdp_tx_drops += n - nxmit;
698 	sq->stats.kicks += kicks;
699 	u64_stats_update_end(&sq->stats.syncp);
700 
701 	virtnet_xdp_put_sq(vi, sq);
702 	return ret;
703 }
704 
705 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
706 {
707 	return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0;
708 }
709 
710 /* We copy the packet for XDP in the following cases:
711  *
712  * 1) Packet is scattered across multiple rx buffers.
713  * 2) Headroom space is insufficient.
714  *
715  * This is inefficient but it's a temporary condition that
716  * we hit right after XDP is enabled and until queue is refilled
717  * with large buffers with sufficient headroom - so it should affect
718  * at most queue size packets.
719  * Afterwards, the conditions to enable
720  * XDP should preclude the underlying device from sending packets
721  * across multiple buffers (num_buf > 1), and we make sure buffers
722  * have enough headroom.
723  */
724 static struct page *xdp_linearize_page(struct receive_queue *rq,
725 				       u16 *num_buf,
726 				       struct page *p,
727 				       int offset,
728 				       int page_off,
729 				       unsigned int *len)
730 {
731 	struct page *page = alloc_page(GFP_ATOMIC);
732 
733 	if (!page)
734 		return NULL;
735 
736 	memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
737 	page_off += *len;
738 
739 	while (--*num_buf) {
740 		int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
741 		unsigned int buflen;
742 		void *buf;
743 		int off;
744 
745 		buf = virtqueue_get_buf(rq->vq, &buflen);
746 		if (unlikely(!buf))
747 			goto err_buf;
748 
749 		p = virt_to_head_page(buf);
750 		off = buf - page_address(p);
751 
752 		/* guard against a misconfigured or uncooperative backend that
753 		 * is sending packet larger than the MTU.
754 		 */
755 		if ((page_off + buflen + tailroom) > PAGE_SIZE) {
756 			put_page(p);
757 			goto err_buf;
758 		}
759 
760 		memcpy(page_address(page) + page_off,
761 		       page_address(p) + off, buflen);
762 		page_off += buflen;
763 		put_page(p);
764 	}
765 
766 	/* Headroom does not contribute to packet length */
767 	*len = page_off - VIRTIO_XDP_HEADROOM;
768 	return page;
769 err_buf:
770 	__free_pages(page, 0);
771 	return NULL;
772 }
773 
774 static struct sk_buff *receive_small(struct net_device *dev,
775 				     struct virtnet_info *vi,
776 				     struct receive_queue *rq,
777 				     void *buf, void *ctx,
778 				     unsigned int len,
779 				     unsigned int *xdp_xmit,
780 				     struct virtnet_rq_stats *stats)
781 {
782 	struct sk_buff *skb;
783 	struct bpf_prog *xdp_prog;
784 	unsigned int xdp_headroom = (unsigned long)ctx;
785 	unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
786 	unsigned int headroom = vi->hdr_len + header_offset;
787 	unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
788 			      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
789 	struct page *page = virt_to_head_page(buf);
790 	unsigned int delta = 0;
791 	struct page *xdp_page;
792 	int err;
793 	unsigned int metasize = 0;
794 
795 	len -= vi->hdr_len;
796 	stats->bytes += len;
797 
798 	if (unlikely(len > GOOD_PACKET_LEN)) {
799 		pr_debug("%s: rx error: len %u exceeds max size %d\n",
800 			 dev->name, len, GOOD_PACKET_LEN);
801 		dev->stats.rx_length_errors++;
802 		goto err;
803 	}
804 
805 	if (likely(!vi->xdp_enabled)) {
806 		xdp_prog = NULL;
807 		goto skip_xdp;
808 	}
809 
810 	rcu_read_lock();
811 	xdp_prog = rcu_dereference(rq->xdp_prog);
812 	if (xdp_prog) {
813 		struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
814 		struct xdp_frame *xdpf;
815 		struct xdp_buff xdp;
816 		void *orig_data;
817 		u32 act;
818 
819 		if (unlikely(hdr->hdr.gso_type))
820 			goto err_xdp;
821 
822 		if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
823 			int offset = buf - page_address(page) + header_offset;
824 			unsigned int tlen = len + vi->hdr_len;
825 			u16 num_buf = 1;
826 
827 			xdp_headroom = virtnet_get_headroom(vi);
828 			header_offset = VIRTNET_RX_PAD + xdp_headroom;
829 			headroom = vi->hdr_len + header_offset;
830 			buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
831 				 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
832 			xdp_page = xdp_linearize_page(rq, &num_buf, page,
833 						      offset, header_offset,
834 						      &tlen);
835 			if (!xdp_page)
836 				goto err_xdp;
837 
838 			buf = page_address(xdp_page);
839 			put_page(page);
840 			page = xdp_page;
841 		}
842 
843 		xdp_init_buff(&xdp, buflen, &rq->xdp_rxq);
844 		xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len,
845 				 xdp_headroom, len, true);
846 		orig_data = xdp.data;
847 		act = bpf_prog_run_xdp(xdp_prog, &xdp);
848 		stats->xdp_packets++;
849 
850 		switch (act) {
851 		case XDP_PASS:
852 			/* Recalculate length in case bpf program changed it */
853 			delta = orig_data - xdp.data;
854 			len = xdp.data_end - xdp.data;
855 			metasize = xdp.data - xdp.data_meta;
856 			break;
857 		case XDP_TX:
858 			stats->xdp_tx++;
859 			xdpf = xdp_convert_buff_to_frame(&xdp);
860 			if (unlikely(!xdpf))
861 				goto err_xdp;
862 			err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
863 			if (unlikely(!err)) {
864 				xdp_return_frame_rx_napi(xdpf);
865 			} else if (unlikely(err < 0)) {
866 				trace_xdp_exception(vi->dev, xdp_prog, act);
867 				goto err_xdp;
868 			}
869 			*xdp_xmit |= VIRTIO_XDP_TX;
870 			rcu_read_unlock();
871 			goto xdp_xmit;
872 		case XDP_REDIRECT:
873 			stats->xdp_redirects++;
874 			err = xdp_do_redirect(dev, &xdp, xdp_prog);
875 			if (err)
876 				goto err_xdp;
877 			*xdp_xmit |= VIRTIO_XDP_REDIR;
878 			rcu_read_unlock();
879 			goto xdp_xmit;
880 		default:
881 			bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
882 			fallthrough;
883 		case XDP_ABORTED:
884 			trace_xdp_exception(vi->dev, xdp_prog, act);
885 			goto err_xdp;
886 		case XDP_DROP:
887 			goto err_xdp;
888 		}
889 	}
890 	rcu_read_unlock();
891 
892 skip_xdp:
893 	skb = build_skb(buf, buflen);
894 	if (!skb)
895 		goto err;
896 	skb_reserve(skb, headroom - delta);
897 	skb_put(skb, len);
898 	if (!xdp_prog) {
899 		buf += header_offset;
900 		memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
901 	} /* keep zeroed vnet hdr since XDP is loaded */
902 
903 	if (metasize)
904 		skb_metadata_set(skb, metasize);
905 
906 	return skb;
907 
908 err_xdp:
909 	rcu_read_unlock();
910 	stats->xdp_drops++;
911 err:
912 	stats->drops++;
913 	put_page(page);
914 xdp_xmit:
915 	return NULL;
916 }
917 
918 static struct sk_buff *receive_big(struct net_device *dev,
919 				   struct virtnet_info *vi,
920 				   struct receive_queue *rq,
921 				   void *buf,
922 				   unsigned int len,
923 				   struct virtnet_rq_stats *stats)
924 {
925 	struct page *page = buf;
926 	struct sk_buff *skb =
927 		page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0, 0);
928 
929 	stats->bytes += len - vi->hdr_len;
930 	if (unlikely(!skb))
931 		goto err;
932 
933 	return skb;
934 
935 err:
936 	stats->drops++;
937 	give_pages(rq, page);
938 	return NULL;
939 }
940 
941 static struct sk_buff *receive_mergeable(struct net_device *dev,
942 					 struct virtnet_info *vi,
943 					 struct receive_queue *rq,
944 					 void *buf,
945 					 void *ctx,
946 					 unsigned int len,
947 					 unsigned int *xdp_xmit,
948 					 struct virtnet_rq_stats *stats)
949 {
950 	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
951 	u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
952 	struct page *page = virt_to_head_page(buf);
953 	int offset = buf - page_address(page);
954 	struct sk_buff *head_skb, *curr_skb;
955 	struct bpf_prog *xdp_prog;
956 	unsigned int truesize = mergeable_ctx_to_truesize(ctx);
957 	unsigned int headroom = mergeable_ctx_to_headroom(ctx);
958 	unsigned int metasize = 0;
959 	unsigned int frame_sz;
960 	int err;
961 
962 	head_skb = NULL;
963 	stats->bytes += len - vi->hdr_len;
964 
965 	if (unlikely(len > truesize)) {
966 		pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
967 			 dev->name, len, (unsigned long)ctx);
968 		dev->stats.rx_length_errors++;
969 		goto err_skb;
970 	}
971 
972 	if (likely(!vi->xdp_enabled)) {
973 		xdp_prog = NULL;
974 		goto skip_xdp;
975 	}
976 
977 	rcu_read_lock();
978 	xdp_prog = rcu_dereference(rq->xdp_prog);
979 	if (xdp_prog) {
980 		struct xdp_frame *xdpf;
981 		struct page *xdp_page;
982 		struct xdp_buff xdp;
983 		void *data;
984 		u32 act;
985 
986 		/* Transient failure which in theory could occur if
987 		 * in-flight packets from before XDP was enabled reach
988 		 * the receive path after XDP is loaded.
989 		 */
990 		if (unlikely(hdr->hdr.gso_type))
991 			goto err_xdp;
992 
993 		/* Buffers with headroom use PAGE_SIZE as alloc size,
994 		 * see add_recvbuf_mergeable() + get_mergeable_buf_len()
995 		 */
996 		frame_sz = headroom ? PAGE_SIZE : truesize;
997 
998 		/* This happens when rx buffer size is underestimated
999 		 * or headroom is not enough because of the buffer
1000 		 * was refilled before XDP is set. This should only
1001 		 * happen for the first several packets, so we don't
1002 		 * care much about its performance.
1003 		 */
1004 		if (unlikely(num_buf > 1 ||
1005 			     headroom < virtnet_get_headroom(vi))) {
1006 			/* linearize data for XDP */
1007 			xdp_page = xdp_linearize_page(rq, &num_buf,
1008 						      page, offset,
1009 						      VIRTIO_XDP_HEADROOM,
1010 						      &len);
1011 			frame_sz = PAGE_SIZE;
1012 
1013 			if (!xdp_page)
1014 				goto err_xdp;
1015 			offset = VIRTIO_XDP_HEADROOM;
1016 		} else {
1017 			xdp_page = page;
1018 		}
1019 
1020 		/* Allow consuming headroom but reserve enough space to push
1021 		 * the descriptor on if we get an XDP_TX return code.
1022 		 */
1023 		data = page_address(xdp_page) + offset;
1024 		xdp_init_buff(&xdp, frame_sz - vi->hdr_len, &rq->xdp_rxq);
1025 		xdp_prepare_buff(&xdp, data - VIRTIO_XDP_HEADROOM + vi->hdr_len,
1026 				 VIRTIO_XDP_HEADROOM, len - vi->hdr_len, true);
1027 
1028 		act = bpf_prog_run_xdp(xdp_prog, &xdp);
1029 		stats->xdp_packets++;
1030 
1031 		switch (act) {
1032 		case XDP_PASS:
1033 			metasize = xdp.data - xdp.data_meta;
1034 
1035 			/* recalculate offset to account for any header
1036 			 * adjustments and minus the metasize to copy the
1037 			 * metadata in page_to_skb(). Note other cases do not
1038 			 * build an skb and avoid using offset
1039 			 */
1040 			offset = xdp.data - page_address(xdp_page) -
1041 				 vi->hdr_len - metasize;
1042 
1043 			/* recalculate len if xdp.data, xdp.data_end or
1044 			 * xdp.data_meta were adjusted
1045 			 */
1046 			len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
1047 
1048 			/* recalculate headroom if xdp.data or xdp_data_meta
1049 			 * were adjusted, note that offset should always point
1050 			 * to the start of the reserved bytes for virtio_net
1051 			 * header which are followed by xdp.data, that means
1052 			 * that offset is equal to the headroom (when buf is
1053 			 * starting at the beginning of the page, otherwise
1054 			 * there is a base offset inside the page) but it's used
1055 			 * with a different starting point (buf start) than
1056 			 * xdp.data (buf start + vnet hdr size). If xdp.data or
1057 			 * data_meta were adjusted by the xdp prog then the
1058 			 * headroom size has changed and so has the offset, we
1059 			 * can use data_hard_start, which points at buf start +
1060 			 * vnet hdr size, to calculate the new headroom and use
1061 			 * it later to compute buf start in page_to_skb()
1062 			 */
1063 			headroom = xdp.data - xdp.data_hard_start - metasize;
1064 
1065 			/* We can only create skb based on xdp_page. */
1066 			if (unlikely(xdp_page != page)) {
1067 				rcu_read_unlock();
1068 				put_page(page);
1069 				head_skb = page_to_skb(vi, rq, xdp_page, offset,
1070 						       len, PAGE_SIZE, false,
1071 						       metasize,
1072 						       headroom);
1073 				return head_skb;
1074 			}
1075 			break;
1076 		case XDP_TX:
1077 			stats->xdp_tx++;
1078 			xdpf = xdp_convert_buff_to_frame(&xdp);
1079 			if (unlikely(!xdpf)) {
1080 				if (unlikely(xdp_page != page))
1081 					put_page(xdp_page);
1082 				goto err_xdp;
1083 			}
1084 			err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
1085 			if (unlikely(!err)) {
1086 				xdp_return_frame_rx_napi(xdpf);
1087 			} else if (unlikely(err < 0)) {
1088 				trace_xdp_exception(vi->dev, xdp_prog, act);
1089 				if (unlikely(xdp_page != page))
1090 					put_page(xdp_page);
1091 				goto err_xdp;
1092 			}
1093 			*xdp_xmit |= VIRTIO_XDP_TX;
1094 			if (unlikely(xdp_page != page))
1095 				put_page(page);
1096 			rcu_read_unlock();
1097 			goto xdp_xmit;
1098 		case XDP_REDIRECT:
1099 			stats->xdp_redirects++;
1100 			err = xdp_do_redirect(dev, &xdp, xdp_prog);
1101 			if (err) {
1102 				if (unlikely(xdp_page != page))
1103 					put_page(xdp_page);
1104 				goto err_xdp;
1105 			}
1106 			*xdp_xmit |= VIRTIO_XDP_REDIR;
1107 			if (unlikely(xdp_page != page))
1108 				put_page(page);
1109 			rcu_read_unlock();
1110 			goto xdp_xmit;
1111 		default:
1112 			bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
1113 			fallthrough;
1114 		case XDP_ABORTED:
1115 			trace_xdp_exception(vi->dev, xdp_prog, act);
1116 			fallthrough;
1117 		case XDP_DROP:
1118 			if (unlikely(xdp_page != page))
1119 				__free_pages(xdp_page, 0);
1120 			goto err_xdp;
1121 		}
1122 	}
1123 	rcu_read_unlock();
1124 
1125 skip_xdp:
1126 	head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
1127 			       metasize, headroom);
1128 	curr_skb = head_skb;
1129 
1130 	if (unlikely(!curr_skb))
1131 		goto err_skb;
1132 	while (--num_buf) {
1133 		int num_skb_frags;
1134 
1135 		buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
1136 		if (unlikely(!buf)) {
1137 			pr_debug("%s: rx error: %d buffers out of %d missing\n",
1138 				 dev->name, num_buf,
1139 				 virtio16_to_cpu(vi->vdev,
1140 						 hdr->num_buffers));
1141 			dev->stats.rx_length_errors++;
1142 			goto err_buf;
1143 		}
1144 
1145 		stats->bytes += len;
1146 		page = virt_to_head_page(buf);
1147 
1148 		truesize = mergeable_ctx_to_truesize(ctx);
1149 		if (unlikely(len > truesize)) {
1150 			pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1151 				 dev->name, len, (unsigned long)ctx);
1152 			dev->stats.rx_length_errors++;
1153 			goto err_skb;
1154 		}
1155 
1156 		num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
1157 		if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
1158 			struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
1159 
1160 			if (unlikely(!nskb))
1161 				goto err_skb;
1162 			if (curr_skb == head_skb)
1163 				skb_shinfo(curr_skb)->frag_list = nskb;
1164 			else
1165 				curr_skb->next = nskb;
1166 			curr_skb = nskb;
1167 			head_skb->truesize += nskb->truesize;
1168 			num_skb_frags = 0;
1169 		}
1170 		if (curr_skb != head_skb) {
1171 			head_skb->data_len += len;
1172 			head_skb->len += len;
1173 			head_skb->truesize += truesize;
1174 		}
1175 		offset = buf - page_address(page);
1176 		if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
1177 			put_page(page);
1178 			skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
1179 					     len, truesize);
1180 		} else {
1181 			skb_add_rx_frag(curr_skb, num_skb_frags, page,
1182 					offset, len, truesize);
1183 		}
1184 	}
1185 
1186 	ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
1187 	return head_skb;
1188 
1189 err_xdp:
1190 	rcu_read_unlock();
1191 	stats->xdp_drops++;
1192 err_skb:
1193 	put_page(page);
1194 	while (num_buf-- > 1) {
1195 		buf = virtqueue_get_buf(rq->vq, &len);
1196 		if (unlikely(!buf)) {
1197 			pr_debug("%s: rx error: %d buffers missing\n",
1198 				 dev->name, num_buf);
1199 			dev->stats.rx_length_errors++;
1200 			break;
1201 		}
1202 		stats->bytes += len;
1203 		page = virt_to_head_page(buf);
1204 		put_page(page);
1205 	}
1206 err_buf:
1207 	stats->drops++;
1208 	dev_kfree_skb(head_skb);
1209 xdp_xmit:
1210 	return NULL;
1211 }
1212 
1213 static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash *hdr_hash,
1214 				struct sk_buff *skb)
1215 {
1216 	enum pkt_hash_types rss_hash_type;
1217 
1218 	if (!hdr_hash || !skb)
1219 		return;
1220 
1221 	switch (__le16_to_cpu(hdr_hash->hash_report)) {
1222 	case VIRTIO_NET_HASH_REPORT_TCPv4:
1223 	case VIRTIO_NET_HASH_REPORT_UDPv4:
1224 	case VIRTIO_NET_HASH_REPORT_TCPv6:
1225 	case VIRTIO_NET_HASH_REPORT_UDPv6:
1226 	case VIRTIO_NET_HASH_REPORT_TCPv6_EX:
1227 	case VIRTIO_NET_HASH_REPORT_UDPv6_EX:
1228 		rss_hash_type = PKT_HASH_TYPE_L4;
1229 		break;
1230 	case VIRTIO_NET_HASH_REPORT_IPv4:
1231 	case VIRTIO_NET_HASH_REPORT_IPv6:
1232 	case VIRTIO_NET_HASH_REPORT_IPv6_EX:
1233 		rss_hash_type = PKT_HASH_TYPE_L3;
1234 		break;
1235 	case VIRTIO_NET_HASH_REPORT_NONE:
1236 	default:
1237 		rss_hash_type = PKT_HASH_TYPE_NONE;
1238 	}
1239 	skb_set_hash(skb, __le32_to_cpu(hdr_hash->hash_value), rss_hash_type);
1240 }
1241 
1242 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
1243 			void *buf, unsigned int len, void **ctx,
1244 			unsigned int *xdp_xmit,
1245 			struct virtnet_rq_stats *stats)
1246 {
1247 	struct net_device *dev = vi->dev;
1248 	struct sk_buff *skb;
1249 	struct virtio_net_hdr_mrg_rxbuf *hdr;
1250 
1251 	if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
1252 		pr_debug("%s: short packet %i\n", dev->name, len);
1253 		dev->stats.rx_length_errors++;
1254 		if (vi->mergeable_rx_bufs) {
1255 			put_page(virt_to_head_page(buf));
1256 		} else if (vi->big_packets) {
1257 			give_pages(rq, buf);
1258 		} else {
1259 			put_page(virt_to_head_page(buf));
1260 		}
1261 		return;
1262 	}
1263 
1264 	if (vi->mergeable_rx_bufs)
1265 		skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1266 					stats);
1267 	else if (vi->big_packets)
1268 		skb = receive_big(dev, vi, rq, buf, len, stats);
1269 	else
1270 		skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1271 
1272 	if (unlikely(!skb))
1273 		return;
1274 
1275 	hdr = skb_vnet_hdr(skb);
1276 	if (dev->features & NETIF_F_RXHASH && vi->has_rss_hash_report)
1277 		virtio_skb_set_hash((const struct virtio_net_hdr_v1_hash *)hdr, skb);
1278 
1279 	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1280 		skb->ip_summed = CHECKSUM_UNNECESSARY;
1281 
1282 	if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1283 				  virtio_is_little_endian(vi->vdev))) {
1284 		net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1285 				     dev->name, hdr->hdr.gso_type,
1286 				     hdr->hdr.gso_size);
1287 		goto frame_err;
1288 	}
1289 
1290 	skb_record_rx_queue(skb, vq2rxq(rq->vq));
1291 	skb->protocol = eth_type_trans(skb, dev);
1292 	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1293 		 ntohs(skb->protocol), skb->len, skb->pkt_type);
1294 
1295 	napi_gro_receive(&rq->napi, skb);
1296 	return;
1297 
1298 frame_err:
1299 	dev->stats.rx_frame_errors++;
1300 	dev_kfree_skb(skb);
1301 }
1302 
1303 /* Unlike mergeable buffers, all buffers are allocated to the
1304  * same size, except for the headroom. For this reason we do
1305  * not need to use  mergeable_len_to_ctx here - it is enough
1306  * to store the headroom as the context ignoring the truesize.
1307  */
1308 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1309 			     gfp_t gfp)
1310 {
1311 	struct page_frag *alloc_frag = &rq->alloc_frag;
1312 	char *buf;
1313 	unsigned int xdp_headroom = virtnet_get_headroom(vi);
1314 	void *ctx = (void *)(unsigned long)xdp_headroom;
1315 	int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1316 	int err;
1317 
1318 	len = SKB_DATA_ALIGN(len) +
1319 	      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1320 	if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1321 		return -ENOMEM;
1322 
1323 	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1324 	get_page(alloc_frag->page);
1325 	alloc_frag->offset += len;
1326 	sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1327 		    vi->hdr_len + GOOD_PACKET_LEN);
1328 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1329 	if (err < 0)
1330 		put_page(virt_to_head_page(buf));
1331 	return err;
1332 }
1333 
1334 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1335 			   gfp_t gfp)
1336 {
1337 	struct page *first, *list = NULL;
1338 	char *p;
1339 	int i, err, offset;
1340 
1341 	sg_init_table(rq->sg, vi->big_packets_num_skbfrags + 2);
1342 
1343 	/* page in rq->sg[vi->big_packets_num_skbfrags + 1] is list tail */
1344 	for (i = vi->big_packets_num_skbfrags + 1; i > 1; --i) {
1345 		first = get_a_page(rq, gfp);
1346 		if (!first) {
1347 			if (list)
1348 				give_pages(rq, list);
1349 			return -ENOMEM;
1350 		}
1351 		sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1352 
1353 		/* chain new page in list head to match sg */
1354 		first->private = (unsigned long)list;
1355 		list = first;
1356 	}
1357 
1358 	first = get_a_page(rq, gfp);
1359 	if (!first) {
1360 		give_pages(rq, list);
1361 		return -ENOMEM;
1362 	}
1363 	p = page_address(first);
1364 
1365 	/* rq->sg[0], rq->sg[1] share the same page */
1366 	/* a separated rq->sg[0] for header - required in case !any_header_sg */
1367 	sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1368 
1369 	/* rq->sg[1] for data packet, from offset */
1370 	offset = sizeof(struct padded_vnet_hdr);
1371 	sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1372 
1373 	/* chain first in list head */
1374 	first->private = (unsigned long)list;
1375 	err = virtqueue_add_inbuf(rq->vq, rq->sg, vi->big_packets_num_skbfrags + 2,
1376 				  first, gfp);
1377 	if (err < 0)
1378 		give_pages(rq, first);
1379 
1380 	return err;
1381 }
1382 
1383 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1384 					  struct ewma_pkt_len *avg_pkt_len,
1385 					  unsigned int room)
1386 {
1387 	struct virtnet_info *vi = rq->vq->vdev->priv;
1388 	const size_t hdr_len = vi->hdr_len;
1389 	unsigned int len;
1390 
1391 	if (room)
1392 		return PAGE_SIZE - room;
1393 
1394 	len = hdr_len +	clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1395 				rq->min_buf_len, PAGE_SIZE - hdr_len);
1396 
1397 	return ALIGN(len, L1_CACHE_BYTES);
1398 }
1399 
1400 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1401 				 struct receive_queue *rq, gfp_t gfp)
1402 {
1403 	struct page_frag *alloc_frag = &rq->alloc_frag;
1404 	unsigned int headroom = virtnet_get_headroom(vi);
1405 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1406 	unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1407 	char *buf;
1408 	void *ctx;
1409 	int err;
1410 	unsigned int len, hole;
1411 
1412 	/* Extra tailroom is needed to satisfy XDP's assumption. This
1413 	 * means rx frags coalescing won't work, but consider we've
1414 	 * disabled GSO for XDP, it won't be a big issue.
1415 	 */
1416 	len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1417 	if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1418 		return -ENOMEM;
1419 
1420 	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1421 	buf += headroom; /* advance address leaving hole at front of pkt */
1422 	get_page(alloc_frag->page);
1423 	alloc_frag->offset += len + room;
1424 	hole = alloc_frag->size - alloc_frag->offset;
1425 	if (hole < len + room) {
1426 		/* To avoid internal fragmentation, if there is very likely not
1427 		 * enough space for another buffer, add the remaining space to
1428 		 * the current buffer.
1429 		 */
1430 		len += hole;
1431 		alloc_frag->offset += hole;
1432 	}
1433 
1434 	sg_init_one(rq->sg, buf, len);
1435 	ctx = mergeable_len_to_ctx(len, headroom);
1436 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1437 	if (err < 0)
1438 		put_page(virt_to_head_page(buf));
1439 
1440 	return err;
1441 }
1442 
1443 /*
1444  * Returns false if we couldn't fill entirely (OOM).
1445  *
1446  * Normally run in the receive path, but can also be run from ndo_open
1447  * before we're receiving packets, or from refill_work which is
1448  * careful to disable receiving (using napi_disable).
1449  */
1450 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1451 			  gfp_t gfp)
1452 {
1453 	int err;
1454 	bool oom;
1455 
1456 	do {
1457 		if (vi->mergeable_rx_bufs)
1458 			err = add_recvbuf_mergeable(vi, rq, gfp);
1459 		else if (vi->big_packets)
1460 			err = add_recvbuf_big(vi, rq, gfp);
1461 		else
1462 			err = add_recvbuf_small(vi, rq, gfp);
1463 
1464 		oom = err == -ENOMEM;
1465 		if (err)
1466 			break;
1467 	} while (rq->vq->num_free);
1468 	if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1469 		unsigned long flags;
1470 
1471 		flags = u64_stats_update_begin_irqsave(&rq->stats.syncp);
1472 		rq->stats.kicks++;
1473 		u64_stats_update_end_irqrestore(&rq->stats.syncp, flags);
1474 	}
1475 
1476 	return !oom;
1477 }
1478 
1479 static void skb_recv_done(struct virtqueue *rvq)
1480 {
1481 	struct virtnet_info *vi = rvq->vdev->priv;
1482 	struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1483 
1484 	virtqueue_napi_schedule(&rq->napi, rvq);
1485 }
1486 
1487 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1488 {
1489 	napi_enable(napi);
1490 
1491 	/* If all buffers were filled by other side before we napi_enabled, we
1492 	 * won't get another interrupt, so process any outstanding packets now.
1493 	 * Call local_bh_enable after to trigger softIRQ processing.
1494 	 */
1495 	local_bh_disable();
1496 	virtqueue_napi_schedule(napi, vq);
1497 	local_bh_enable();
1498 }
1499 
1500 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1501 				   struct virtqueue *vq,
1502 				   struct napi_struct *napi)
1503 {
1504 	if (!napi->weight)
1505 		return;
1506 
1507 	/* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1508 	 * enable the feature if this is likely affine with the transmit path.
1509 	 */
1510 	if (!vi->affinity_hint_set) {
1511 		napi->weight = 0;
1512 		return;
1513 	}
1514 
1515 	return virtnet_napi_enable(vq, napi);
1516 }
1517 
1518 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1519 {
1520 	if (napi->weight)
1521 		napi_disable(napi);
1522 }
1523 
1524 static void refill_work(struct work_struct *work)
1525 {
1526 	struct virtnet_info *vi =
1527 		container_of(work, struct virtnet_info, refill.work);
1528 	bool still_empty;
1529 	int i;
1530 
1531 	for (i = 0; i < vi->curr_queue_pairs; i++) {
1532 		struct receive_queue *rq = &vi->rq[i];
1533 
1534 		napi_disable(&rq->napi);
1535 		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1536 		virtnet_napi_enable(rq->vq, &rq->napi);
1537 
1538 		/* In theory, this can happen: if we don't get any buffers in
1539 		 * we will *never* try to fill again.
1540 		 */
1541 		if (still_empty)
1542 			schedule_delayed_work(&vi->refill, HZ/2);
1543 	}
1544 }
1545 
1546 static int virtnet_receive(struct receive_queue *rq, int budget,
1547 			   unsigned int *xdp_xmit)
1548 {
1549 	struct virtnet_info *vi = rq->vq->vdev->priv;
1550 	struct virtnet_rq_stats stats = {};
1551 	unsigned int len;
1552 	void *buf;
1553 	int i;
1554 
1555 	if (!vi->big_packets || vi->mergeable_rx_bufs) {
1556 		void *ctx;
1557 
1558 		while (stats.packets < budget &&
1559 		       (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1560 			receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1561 			stats.packets++;
1562 		}
1563 	} else {
1564 		while (stats.packets < budget &&
1565 		       (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1566 			receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1567 			stats.packets++;
1568 		}
1569 	}
1570 
1571 	if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
1572 		if (!try_fill_recv(vi, rq, GFP_ATOMIC)) {
1573 			spin_lock(&vi->refill_lock);
1574 			if (vi->refill_enabled)
1575 				schedule_delayed_work(&vi->refill, 0);
1576 			spin_unlock(&vi->refill_lock);
1577 		}
1578 	}
1579 
1580 	u64_stats_update_begin(&rq->stats.syncp);
1581 	for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1582 		size_t offset = virtnet_rq_stats_desc[i].offset;
1583 		u64 *item;
1584 
1585 		item = (u64 *)((u8 *)&rq->stats + offset);
1586 		*item += *(u64 *)((u8 *)&stats + offset);
1587 	}
1588 	u64_stats_update_end(&rq->stats.syncp);
1589 
1590 	return stats.packets;
1591 }
1592 
1593 static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
1594 {
1595 	unsigned int len;
1596 	unsigned int packets = 0;
1597 	unsigned int bytes = 0;
1598 	void *ptr;
1599 
1600 	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1601 		if (likely(!is_xdp_frame(ptr))) {
1602 			struct sk_buff *skb = ptr;
1603 
1604 			pr_debug("Sent skb %p\n", skb);
1605 
1606 			bytes += skb->len;
1607 			napi_consume_skb(skb, in_napi);
1608 		} else {
1609 			struct xdp_frame *frame = ptr_to_xdp(ptr);
1610 
1611 			bytes += frame->len;
1612 			xdp_return_frame(frame);
1613 		}
1614 		packets++;
1615 	}
1616 
1617 	/* Avoid overhead when no packets have been processed
1618 	 * happens when called speculatively from start_xmit.
1619 	 */
1620 	if (!packets)
1621 		return;
1622 
1623 	u64_stats_update_begin(&sq->stats.syncp);
1624 	sq->stats.bytes += bytes;
1625 	sq->stats.packets += packets;
1626 	u64_stats_update_end(&sq->stats.syncp);
1627 }
1628 
1629 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
1630 {
1631 	if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
1632 		return false;
1633 	else if (q < vi->curr_queue_pairs)
1634 		return true;
1635 	else
1636 		return false;
1637 }
1638 
1639 static void virtnet_poll_cleantx(struct receive_queue *rq)
1640 {
1641 	struct virtnet_info *vi = rq->vq->vdev->priv;
1642 	unsigned int index = vq2rxq(rq->vq);
1643 	struct send_queue *sq = &vi->sq[index];
1644 	struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1645 
1646 	if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
1647 		return;
1648 
1649 	if (__netif_tx_trylock(txq)) {
1650 		if (sq->reset) {
1651 			__netif_tx_unlock(txq);
1652 			return;
1653 		}
1654 
1655 		do {
1656 			virtqueue_disable_cb(sq->vq);
1657 			free_old_xmit_skbs(sq, true);
1658 		} while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
1659 
1660 		if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1661 			netif_tx_wake_queue(txq);
1662 
1663 		__netif_tx_unlock(txq);
1664 	}
1665 }
1666 
1667 static int virtnet_poll(struct napi_struct *napi, int budget)
1668 {
1669 	struct receive_queue *rq =
1670 		container_of(napi, struct receive_queue, napi);
1671 	struct virtnet_info *vi = rq->vq->vdev->priv;
1672 	struct send_queue *sq;
1673 	unsigned int received;
1674 	unsigned int xdp_xmit = 0;
1675 
1676 	virtnet_poll_cleantx(rq);
1677 
1678 	received = virtnet_receive(rq, budget, &xdp_xmit);
1679 
1680 	/* Out of packets? */
1681 	if (received < budget)
1682 		virtqueue_napi_complete(napi, rq->vq, received);
1683 
1684 	if (xdp_xmit & VIRTIO_XDP_REDIR)
1685 		xdp_do_flush();
1686 
1687 	if (xdp_xmit & VIRTIO_XDP_TX) {
1688 		sq = virtnet_xdp_get_sq(vi);
1689 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1690 			u64_stats_update_begin(&sq->stats.syncp);
1691 			sq->stats.kicks++;
1692 			u64_stats_update_end(&sq->stats.syncp);
1693 		}
1694 		virtnet_xdp_put_sq(vi, sq);
1695 	}
1696 
1697 	return received;
1698 }
1699 
1700 static int virtnet_open(struct net_device *dev)
1701 {
1702 	struct virtnet_info *vi = netdev_priv(dev);
1703 	int i, err;
1704 
1705 	enable_delayed_refill(vi);
1706 
1707 	for (i = 0; i < vi->max_queue_pairs; i++) {
1708 		if (i < vi->curr_queue_pairs)
1709 			/* Make sure we have some buffers: if oom use wq. */
1710 			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1711 				schedule_delayed_work(&vi->refill, 0);
1712 
1713 		err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i, vi->rq[i].napi.napi_id);
1714 		if (err < 0)
1715 			return err;
1716 
1717 		err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1718 						 MEM_TYPE_PAGE_SHARED, NULL);
1719 		if (err < 0) {
1720 			xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1721 			return err;
1722 		}
1723 
1724 		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1725 		virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1726 	}
1727 
1728 	return 0;
1729 }
1730 
1731 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1732 {
1733 	struct send_queue *sq = container_of(napi, struct send_queue, napi);
1734 	struct virtnet_info *vi = sq->vq->vdev->priv;
1735 	unsigned int index = vq2txq(sq->vq);
1736 	struct netdev_queue *txq;
1737 	int opaque;
1738 	bool done;
1739 
1740 	if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
1741 		/* We don't need to enable cb for XDP */
1742 		napi_complete_done(napi, 0);
1743 		return 0;
1744 	}
1745 
1746 	txq = netdev_get_tx_queue(vi->dev, index);
1747 	__netif_tx_lock(txq, raw_smp_processor_id());
1748 	virtqueue_disable_cb(sq->vq);
1749 	free_old_xmit_skbs(sq, true);
1750 
1751 	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1752 		netif_tx_wake_queue(txq);
1753 
1754 	opaque = virtqueue_enable_cb_prepare(sq->vq);
1755 
1756 	done = napi_complete_done(napi, 0);
1757 
1758 	if (!done)
1759 		virtqueue_disable_cb(sq->vq);
1760 
1761 	__netif_tx_unlock(txq);
1762 
1763 	if (done) {
1764 		if (unlikely(virtqueue_poll(sq->vq, opaque))) {
1765 			if (napi_schedule_prep(napi)) {
1766 				__netif_tx_lock(txq, raw_smp_processor_id());
1767 				virtqueue_disable_cb(sq->vq);
1768 				__netif_tx_unlock(txq);
1769 				__napi_schedule(napi);
1770 			}
1771 		}
1772 	}
1773 
1774 	return 0;
1775 }
1776 
1777 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1778 {
1779 	struct virtio_net_hdr_mrg_rxbuf *hdr;
1780 	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1781 	struct virtnet_info *vi = sq->vq->vdev->priv;
1782 	int num_sg;
1783 	unsigned hdr_len = vi->hdr_len;
1784 	bool can_push;
1785 
1786 	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1787 
1788 	can_push = vi->any_header_sg &&
1789 		!((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1790 		!skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1791 	/* Even if we can, don't push here yet as this would skew
1792 	 * csum_start offset below. */
1793 	if (can_push)
1794 		hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1795 	else
1796 		hdr = skb_vnet_hdr(skb);
1797 
1798 	if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1799 				    virtio_is_little_endian(vi->vdev), false,
1800 				    0))
1801 		return -EPROTO;
1802 
1803 	if (vi->mergeable_rx_bufs)
1804 		hdr->num_buffers = 0;
1805 
1806 	sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1807 	if (can_push) {
1808 		__skb_push(skb, hdr_len);
1809 		num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1810 		if (unlikely(num_sg < 0))
1811 			return num_sg;
1812 		/* Pull header back to avoid skew in tx bytes calculations. */
1813 		__skb_pull(skb, hdr_len);
1814 	} else {
1815 		sg_set_buf(sq->sg, hdr, hdr_len);
1816 		num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1817 		if (unlikely(num_sg < 0))
1818 			return num_sg;
1819 		num_sg++;
1820 	}
1821 	return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1822 }
1823 
1824 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1825 {
1826 	struct virtnet_info *vi = netdev_priv(dev);
1827 	int qnum = skb_get_queue_mapping(skb);
1828 	struct send_queue *sq = &vi->sq[qnum];
1829 	int err;
1830 	struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1831 	bool kick = !netdev_xmit_more();
1832 	bool use_napi = sq->napi.weight;
1833 
1834 	/* Free up any pending old buffers before queueing new ones. */
1835 	do {
1836 		if (use_napi)
1837 			virtqueue_disable_cb(sq->vq);
1838 
1839 		free_old_xmit_skbs(sq, false);
1840 
1841 	} while (use_napi && kick &&
1842 	       unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
1843 
1844 	/* timestamp packet in software */
1845 	skb_tx_timestamp(skb);
1846 
1847 	/* Try to transmit */
1848 	err = xmit_skb(sq, skb);
1849 
1850 	/* This should not happen! */
1851 	if (unlikely(err)) {
1852 		dev->stats.tx_fifo_errors++;
1853 		if (net_ratelimit())
1854 			dev_warn(&dev->dev,
1855 				 "Unexpected TXQ (%d) queue failure: %d\n",
1856 				 qnum, err);
1857 		dev->stats.tx_dropped++;
1858 		dev_kfree_skb_any(skb);
1859 		return NETDEV_TX_OK;
1860 	}
1861 
1862 	/* Don't wait up for transmitted skbs to be freed. */
1863 	if (!use_napi) {
1864 		skb_orphan(skb);
1865 		nf_reset_ct(skb);
1866 	}
1867 
1868 	/* If running out of space, stop queue to avoid getting packets that we
1869 	 * are then unable to transmit.
1870 	 * An alternative would be to force queuing layer to requeue the skb by
1871 	 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1872 	 * returned in a normal path of operation: it means that driver is not
1873 	 * maintaining the TX queue stop/start state properly, and causes
1874 	 * the stack to do a non-trivial amount of useless work.
1875 	 * Since most packets only take 1 or 2 ring slots, stopping the queue
1876 	 * early means 16 slots are typically wasted.
1877 	 */
1878 	if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1879 		netif_stop_subqueue(dev, qnum);
1880 		if (use_napi) {
1881 			if (unlikely(!virtqueue_enable_cb_delayed(sq->vq)))
1882 				virtqueue_napi_schedule(&sq->napi, sq->vq);
1883 		} else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1884 			/* More just got used, free them then recheck. */
1885 			free_old_xmit_skbs(sq, false);
1886 			if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1887 				netif_start_subqueue(dev, qnum);
1888 				virtqueue_disable_cb(sq->vq);
1889 			}
1890 		}
1891 	}
1892 
1893 	if (kick || netif_xmit_stopped(txq)) {
1894 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1895 			u64_stats_update_begin(&sq->stats.syncp);
1896 			sq->stats.kicks++;
1897 			u64_stats_update_end(&sq->stats.syncp);
1898 		}
1899 	}
1900 
1901 	return NETDEV_TX_OK;
1902 }
1903 
1904 static int virtnet_rx_resize(struct virtnet_info *vi,
1905 			     struct receive_queue *rq, u32 ring_num)
1906 {
1907 	bool running = netif_running(vi->dev);
1908 	int err, qindex;
1909 
1910 	qindex = rq - vi->rq;
1911 
1912 	if (running)
1913 		napi_disable(&rq->napi);
1914 
1915 	err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf);
1916 	if (err)
1917 		netdev_err(vi->dev, "resize rx fail: rx queue index: %d err: %d\n", qindex, err);
1918 
1919 	if (!try_fill_recv(vi, rq, GFP_KERNEL))
1920 		schedule_delayed_work(&vi->refill, 0);
1921 
1922 	if (running)
1923 		virtnet_napi_enable(rq->vq, &rq->napi);
1924 	return err;
1925 }
1926 
1927 static int virtnet_tx_resize(struct virtnet_info *vi,
1928 			     struct send_queue *sq, u32 ring_num)
1929 {
1930 	bool running = netif_running(vi->dev);
1931 	struct netdev_queue *txq;
1932 	int err, qindex;
1933 
1934 	qindex = sq - vi->sq;
1935 
1936 	if (running)
1937 		virtnet_napi_tx_disable(&sq->napi);
1938 
1939 	txq = netdev_get_tx_queue(vi->dev, qindex);
1940 
1941 	/* 1. wait all ximt complete
1942 	 * 2. fix the race of netif_stop_subqueue() vs netif_start_subqueue()
1943 	 */
1944 	__netif_tx_lock_bh(txq);
1945 
1946 	/* Prevent rx poll from accessing sq. */
1947 	sq->reset = true;
1948 
1949 	/* Prevent the upper layer from trying to send packets. */
1950 	netif_stop_subqueue(vi->dev, qindex);
1951 
1952 	__netif_tx_unlock_bh(txq);
1953 
1954 	err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
1955 	if (err)
1956 		netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
1957 
1958 	__netif_tx_lock_bh(txq);
1959 	sq->reset = false;
1960 	netif_tx_wake_queue(txq);
1961 	__netif_tx_unlock_bh(txq);
1962 
1963 	if (running)
1964 		virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
1965 	return err;
1966 }
1967 
1968 /*
1969  * Send command via the control virtqueue and check status.  Commands
1970  * supported by the hypervisor, as indicated by feature bits, should
1971  * never fail unless improperly formatted.
1972  */
1973 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1974 				 struct scatterlist *out)
1975 {
1976 	struct scatterlist *sgs[4], hdr, stat;
1977 	unsigned out_num = 0, tmp;
1978 	int ret;
1979 
1980 	/* Caller should know better */
1981 	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1982 
1983 	vi->ctrl->status = ~0;
1984 	vi->ctrl->hdr.class = class;
1985 	vi->ctrl->hdr.cmd = cmd;
1986 	/* Add header */
1987 	sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1988 	sgs[out_num++] = &hdr;
1989 
1990 	if (out)
1991 		sgs[out_num++] = out;
1992 
1993 	/* Add return status. */
1994 	sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1995 	sgs[out_num] = &stat;
1996 
1997 	BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1998 	ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1999 	if (ret < 0) {
2000 		dev_warn(&vi->vdev->dev,
2001 			 "Failed to add sgs for command vq: %d\n.", ret);
2002 		return false;
2003 	}
2004 
2005 	if (unlikely(!virtqueue_kick(vi->cvq)))
2006 		return vi->ctrl->status == VIRTIO_NET_OK;
2007 
2008 	/* Spin for a response, the kick causes an ioport write, trapping
2009 	 * into the hypervisor, so the request should be handled immediately.
2010 	 */
2011 	while (!virtqueue_get_buf(vi->cvq, &tmp) &&
2012 	       !virtqueue_is_broken(vi->cvq))
2013 		cpu_relax();
2014 
2015 	return vi->ctrl->status == VIRTIO_NET_OK;
2016 }
2017 
2018 static int virtnet_set_mac_address(struct net_device *dev, void *p)
2019 {
2020 	struct virtnet_info *vi = netdev_priv(dev);
2021 	struct virtio_device *vdev = vi->vdev;
2022 	int ret;
2023 	struct sockaddr *addr;
2024 	struct scatterlist sg;
2025 
2026 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2027 		return -EOPNOTSUPP;
2028 
2029 	addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
2030 	if (!addr)
2031 		return -ENOMEM;
2032 
2033 	ret = eth_prepare_mac_addr_change(dev, addr);
2034 	if (ret)
2035 		goto out;
2036 
2037 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
2038 		sg_init_one(&sg, addr->sa_data, dev->addr_len);
2039 		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2040 					  VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
2041 			dev_warn(&vdev->dev,
2042 				 "Failed to set mac address by vq command.\n");
2043 			ret = -EINVAL;
2044 			goto out;
2045 		}
2046 	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
2047 		   !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
2048 		unsigned int i;
2049 
2050 		/* Naturally, this has an atomicity problem. */
2051 		for (i = 0; i < dev->addr_len; i++)
2052 			virtio_cwrite8(vdev,
2053 				       offsetof(struct virtio_net_config, mac) +
2054 				       i, addr->sa_data[i]);
2055 	}
2056 
2057 	eth_commit_mac_addr_change(dev, p);
2058 	ret = 0;
2059 
2060 out:
2061 	kfree(addr);
2062 	return ret;
2063 }
2064 
2065 static void virtnet_stats(struct net_device *dev,
2066 			  struct rtnl_link_stats64 *tot)
2067 {
2068 	struct virtnet_info *vi = netdev_priv(dev);
2069 	unsigned int start;
2070 	int i;
2071 
2072 	for (i = 0; i < vi->max_queue_pairs; i++) {
2073 		u64 tpackets, tbytes, terrors, rpackets, rbytes, rdrops;
2074 		struct receive_queue *rq = &vi->rq[i];
2075 		struct send_queue *sq = &vi->sq[i];
2076 
2077 		do {
2078 			start = u64_stats_fetch_begin(&sq->stats.syncp);
2079 			tpackets = sq->stats.packets;
2080 			tbytes   = sq->stats.bytes;
2081 			terrors  = sq->stats.tx_timeouts;
2082 		} while (u64_stats_fetch_retry(&sq->stats.syncp, start));
2083 
2084 		do {
2085 			start = u64_stats_fetch_begin(&rq->stats.syncp);
2086 			rpackets = rq->stats.packets;
2087 			rbytes   = rq->stats.bytes;
2088 			rdrops   = rq->stats.drops;
2089 		} while (u64_stats_fetch_retry(&rq->stats.syncp, start));
2090 
2091 		tot->rx_packets += rpackets;
2092 		tot->tx_packets += tpackets;
2093 		tot->rx_bytes   += rbytes;
2094 		tot->tx_bytes   += tbytes;
2095 		tot->rx_dropped += rdrops;
2096 		tot->tx_errors  += terrors;
2097 	}
2098 
2099 	tot->tx_dropped = dev->stats.tx_dropped;
2100 	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
2101 	tot->rx_length_errors = dev->stats.rx_length_errors;
2102 	tot->rx_frame_errors = dev->stats.rx_frame_errors;
2103 }
2104 
2105 static void virtnet_ack_link_announce(struct virtnet_info *vi)
2106 {
2107 	rtnl_lock();
2108 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
2109 				  VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
2110 		dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
2111 	rtnl_unlock();
2112 }
2113 
2114 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
2115 {
2116 	struct scatterlist sg;
2117 	struct net_device *dev = vi->dev;
2118 
2119 	if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
2120 		return 0;
2121 
2122 	vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
2123 	sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
2124 
2125 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
2126 				  VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
2127 		dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
2128 			 queue_pairs);
2129 		return -EINVAL;
2130 	} else {
2131 		vi->curr_queue_pairs = queue_pairs;
2132 		/* virtnet_open() will refill when device is going to up. */
2133 		if (dev->flags & IFF_UP)
2134 			schedule_delayed_work(&vi->refill, 0);
2135 	}
2136 
2137 	return 0;
2138 }
2139 
2140 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
2141 {
2142 	int err;
2143 
2144 	rtnl_lock();
2145 	err = _virtnet_set_queues(vi, queue_pairs);
2146 	rtnl_unlock();
2147 	return err;
2148 }
2149 
2150 static int virtnet_close(struct net_device *dev)
2151 {
2152 	struct virtnet_info *vi = netdev_priv(dev);
2153 	int i;
2154 
2155 	/* Make sure NAPI doesn't schedule refill work */
2156 	disable_delayed_refill(vi);
2157 	/* Make sure refill_work doesn't re-enable napi! */
2158 	cancel_delayed_work_sync(&vi->refill);
2159 
2160 	for (i = 0; i < vi->max_queue_pairs; i++) {
2161 		xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
2162 		napi_disable(&vi->rq[i].napi);
2163 		virtnet_napi_tx_disable(&vi->sq[i].napi);
2164 	}
2165 
2166 	return 0;
2167 }
2168 
2169 static void virtnet_set_rx_mode(struct net_device *dev)
2170 {
2171 	struct virtnet_info *vi = netdev_priv(dev);
2172 	struct scatterlist sg[2];
2173 	struct virtio_net_ctrl_mac *mac_data;
2174 	struct netdev_hw_addr *ha;
2175 	int uc_count;
2176 	int mc_count;
2177 	void *buf;
2178 	int i;
2179 
2180 	/* We can't dynamically set ndo_set_rx_mode, so return gracefully */
2181 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
2182 		return;
2183 
2184 	vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
2185 	vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
2186 
2187 	sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
2188 
2189 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
2190 				  VIRTIO_NET_CTRL_RX_PROMISC, sg))
2191 		dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
2192 			 vi->ctrl->promisc ? "en" : "dis");
2193 
2194 	sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
2195 
2196 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
2197 				  VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
2198 		dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
2199 			 vi->ctrl->allmulti ? "en" : "dis");
2200 
2201 	uc_count = netdev_uc_count(dev);
2202 	mc_count = netdev_mc_count(dev);
2203 	/* MAC filter - use one buffer for both lists */
2204 	buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
2205 		      (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
2206 	mac_data = buf;
2207 	if (!buf)
2208 		return;
2209 
2210 	sg_init_table(sg, 2);
2211 
2212 	/* Store the unicast list and count in the front of the buffer */
2213 	mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
2214 	i = 0;
2215 	netdev_for_each_uc_addr(ha, dev)
2216 		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2217 
2218 	sg_set_buf(&sg[0], mac_data,
2219 		   sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
2220 
2221 	/* multicast list and count fill the end */
2222 	mac_data = (void *)&mac_data->macs[uc_count][0];
2223 
2224 	mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
2225 	i = 0;
2226 	netdev_for_each_mc_addr(ha, dev)
2227 		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2228 
2229 	sg_set_buf(&sg[1], mac_data,
2230 		   sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
2231 
2232 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2233 				  VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
2234 		dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
2235 
2236 	kfree(buf);
2237 }
2238 
2239 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
2240 				   __be16 proto, u16 vid)
2241 {
2242 	struct virtnet_info *vi = netdev_priv(dev);
2243 	struct scatterlist sg;
2244 
2245 	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2246 	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2247 
2248 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2249 				  VIRTIO_NET_CTRL_VLAN_ADD, &sg))
2250 		dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
2251 	return 0;
2252 }
2253 
2254 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
2255 				    __be16 proto, u16 vid)
2256 {
2257 	struct virtnet_info *vi = netdev_priv(dev);
2258 	struct scatterlist sg;
2259 
2260 	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2261 	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2262 
2263 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2264 				  VIRTIO_NET_CTRL_VLAN_DEL, &sg))
2265 		dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
2266 	return 0;
2267 }
2268 
2269 static void virtnet_clean_affinity(struct virtnet_info *vi)
2270 {
2271 	int i;
2272 
2273 	if (vi->affinity_hint_set) {
2274 		for (i = 0; i < vi->max_queue_pairs; i++) {
2275 			virtqueue_set_affinity(vi->rq[i].vq, NULL);
2276 			virtqueue_set_affinity(vi->sq[i].vq, NULL);
2277 		}
2278 
2279 		vi->affinity_hint_set = false;
2280 	}
2281 }
2282 
2283 static void virtnet_set_affinity(struct virtnet_info *vi)
2284 {
2285 	cpumask_var_t mask;
2286 	int stragglers;
2287 	int group_size;
2288 	int i, j, cpu;
2289 	int num_cpu;
2290 	int stride;
2291 
2292 	if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
2293 		virtnet_clean_affinity(vi);
2294 		return;
2295 	}
2296 
2297 	num_cpu = num_online_cpus();
2298 	stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
2299 	stragglers = num_cpu >= vi->curr_queue_pairs ?
2300 			num_cpu % vi->curr_queue_pairs :
2301 			0;
2302 	cpu = cpumask_first(cpu_online_mask);
2303 
2304 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2305 		group_size = stride + (i < stragglers ? 1 : 0);
2306 
2307 		for (j = 0; j < group_size; j++) {
2308 			cpumask_set_cpu(cpu, mask);
2309 			cpu = cpumask_next_wrap(cpu, cpu_online_mask,
2310 						nr_cpu_ids, false);
2311 		}
2312 		virtqueue_set_affinity(vi->rq[i].vq, mask);
2313 		virtqueue_set_affinity(vi->sq[i].vq, mask);
2314 		__netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, XPS_CPUS);
2315 		cpumask_clear(mask);
2316 	}
2317 
2318 	vi->affinity_hint_set = true;
2319 	free_cpumask_var(mask);
2320 }
2321 
2322 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
2323 {
2324 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2325 						   node);
2326 	virtnet_set_affinity(vi);
2327 	return 0;
2328 }
2329 
2330 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
2331 {
2332 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2333 						   node_dead);
2334 	virtnet_set_affinity(vi);
2335 	return 0;
2336 }
2337 
2338 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
2339 {
2340 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2341 						   node);
2342 
2343 	virtnet_clean_affinity(vi);
2344 	return 0;
2345 }
2346 
2347 static enum cpuhp_state virtionet_online;
2348 
2349 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
2350 {
2351 	int ret;
2352 
2353 	ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
2354 	if (ret)
2355 		return ret;
2356 	ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2357 					       &vi->node_dead);
2358 	if (!ret)
2359 		return ret;
2360 	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2361 	return ret;
2362 }
2363 
2364 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
2365 {
2366 	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2367 	cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2368 					    &vi->node_dead);
2369 }
2370 
2371 static void virtnet_get_ringparam(struct net_device *dev,
2372 				  struct ethtool_ringparam *ring,
2373 				  struct kernel_ethtool_ringparam *kernel_ring,
2374 				  struct netlink_ext_ack *extack)
2375 {
2376 	struct virtnet_info *vi = netdev_priv(dev);
2377 
2378 	ring->rx_max_pending = vi->rq[0].vq->num_max;
2379 	ring->tx_max_pending = vi->sq[0].vq->num_max;
2380 	ring->rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2381 	ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2382 }
2383 
2384 static int virtnet_set_ringparam(struct net_device *dev,
2385 				 struct ethtool_ringparam *ring,
2386 				 struct kernel_ethtool_ringparam *kernel_ring,
2387 				 struct netlink_ext_ack *extack)
2388 {
2389 	struct virtnet_info *vi = netdev_priv(dev);
2390 	u32 rx_pending, tx_pending;
2391 	struct receive_queue *rq;
2392 	struct send_queue *sq;
2393 	int i, err;
2394 
2395 	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
2396 		return -EINVAL;
2397 
2398 	rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2399 	tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2400 
2401 	if (ring->rx_pending == rx_pending &&
2402 	    ring->tx_pending == tx_pending)
2403 		return 0;
2404 
2405 	if (ring->rx_pending > vi->rq[0].vq->num_max)
2406 		return -EINVAL;
2407 
2408 	if (ring->tx_pending > vi->sq[0].vq->num_max)
2409 		return -EINVAL;
2410 
2411 	for (i = 0; i < vi->max_queue_pairs; i++) {
2412 		rq = vi->rq + i;
2413 		sq = vi->sq + i;
2414 
2415 		if (ring->tx_pending != tx_pending) {
2416 			err = virtnet_tx_resize(vi, sq, ring->tx_pending);
2417 			if (err)
2418 				return err;
2419 		}
2420 
2421 		if (ring->rx_pending != rx_pending) {
2422 			err = virtnet_rx_resize(vi, rq, ring->rx_pending);
2423 			if (err)
2424 				return err;
2425 		}
2426 	}
2427 
2428 	return 0;
2429 }
2430 
2431 static bool virtnet_commit_rss_command(struct virtnet_info *vi)
2432 {
2433 	struct net_device *dev = vi->dev;
2434 	struct scatterlist sgs[4];
2435 	unsigned int sg_buf_size;
2436 
2437 	/* prepare sgs */
2438 	sg_init_table(sgs, 4);
2439 
2440 	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, indirection_table);
2441 	sg_set_buf(&sgs[0], &vi->ctrl->rss, sg_buf_size);
2442 
2443 	sg_buf_size = sizeof(uint16_t) * (vi->ctrl->rss.indirection_table_mask + 1);
2444 	sg_set_buf(&sgs[1], vi->ctrl->rss.indirection_table, sg_buf_size);
2445 
2446 	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, key)
2447 			- offsetof(struct virtio_net_ctrl_rss, max_tx_vq);
2448 	sg_set_buf(&sgs[2], &vi->ctrl->rss.max_tx_vq, sg_buf_size);
2449 
2450 	sg_buf_size = vi->rss_key_size;
2451 	sg_set_buf(&sgs[3], vi->ctrl->rss.key, sg_buf_size);
2452 
2453 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
2454 				  vi->has_rss ? VIRTIO_NET_CTRL_MQ_RSS_CONFIG
2455 				  : VIRTIO_NET_CTRL_MQ_HASH_CONFIG, sgs)) {
2456 		dev_warn(&dev->dev, "VIRTIONET issue with committing RSS sgs\n");
2457 		return false;
2458 	}
2459 	return true;
2460 }
2461 
2462 static void virtnet_init_default_rss(struct virtnet_info *vi)
2463 {
2464 	u32 indir_val = 0;
2465 	int i = 0;
2466 
2467 	vi->ctrl->rss.hash_types = vi->rss_hash_types_supported;
2468 	vi->rss_hash_types_saved = vi->rss_hash_types_supported;
2469 	vi->ctrl->rss.indirection_table_mask = vi->rss_indir_table_size
2470 						? vi->rss_indir_table_size - 1 : 0;
2471 	vi->ctrl->rss.unclassified_queue = 0;
2472 
2473 	for (; i < vi->rss_indir_table_size; ++i) {
2474 		indir_val = ethtool_rxfh_indir_default(i, vi->curr_queue_pairs);
2475 		vi->ctrl->rss.indirection_table[i] = indir_val;
2476 	}
2477 
2478 	vi->ctrl->rss.max_tx_vq = vi->curr_queue_pairs;
2479 	vi->ctrl->rss.hash_key_length = vi->rss_key_size;
2480 
2481 	netdev_rss_key_fill(vi->ctrl->rss.key, vi->rss_key_size);
2482 }
2483 
2484 static void virtnet_get_hashflow(const struct virtnet_info *vi, struct ethtool_rxnfc *info)
2485 {
2486 	info->data = 0;
2487 	switch (info->flow_type) {
2488 	case TCP_V4_FLOW:
2489 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) {
2490 			info->data = RXH_IP_SRC | RXH_IP_DST |
2491 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2492 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
2493 			info->data = RXH_IP_SRC | RXH_IP_DST;
2494 		}
2495 		break;
2496 	case TCP_V6_FLOW:
2497 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) {
2498 			info->data = RXH_IP_SRC | RXH_IP_DST |
2499 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2500 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
2501 			info->data = RXH_IP_SRC | RXH_IP_DST;
2502 		}
2503 		break;
2504 	case UDP_V4_FLOW:
2505 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
2506 			info->data = RXH_IP_SRC | RXH_IP_DST |
2507 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2508 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
2509 			info->data = RXH_IP_SRC | RXH_IP_DST;
2510 		}
2511 		break;
2512 	case UDP_V6_FLOW:
2513 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) {
2514 			info->data = RXH_IP_SRC | RXH_IP_DST |
2515 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2516 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
2517 			info->data = RXH_IP_SRC | RXH_IP_DST;
2518 		}
2519 		break;
2520 	case IPV4_FLOW:
2521 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4)
2522 			info->data = RXH_IP_SRC | RXH_IP_DST;
2523 
2524 		break;
2525 	case IPV6_FLOW:
2526 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6)
2527 			info->data = RXH_IP_SRC | RXH_IP_DST;
2528 
2529 		break;
2530 	default:
2531 		info->data = 0;
2532 		break;
2533 	}
2534 }
2535 
2536 static bool virtnet_set_hashflow(struct virtnet_info *vi, struct ethtool_rxnfc *info)
2537 {
2538 	u32 new_hashtypes = vi->rss_hash_types_saved;
2539 	bool is_disable = info->data & RXH_DISCARD;
2540 	bool is_l4 = info->data == (RXH_IP_SRC | RXH_IP_DST | RXH_L4_B_0_1 | RXH_L4_B_2_3);
2541 
2542 	/* supports only 'sd', 'sdfn' and 'r' */
2543 	if (!((info->data == (RXH_IP_SRC | RXH_IP_DST)) | is_l4 | is_disable))
2544 		return false;
2545 
2546 	switch (info->flow_type) {
2547 	case TCP_V4_FLOW:
2548 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_TCPv4);
2549 		if (!is_disable)
2550 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4
2551 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_TCPv4 : 0);
2552 		break;
2553 	case UDP_V4_FLOW:
2554 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_UDPv4);
2555 		if (!is_disable)
2556 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4
2557 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv4 : 0);
2558 		break;
2559 	case IPV4_FLOW:
2560 		new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv4;
2561 		if (!is_disable)
2562 			new_hashtypes = VIRTIO_NET_RSS_HASH_TYPE_IPv4;
2563 		break;
2564 	case TCP_V6_FLOW:
2565 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv6 | VIRTIO_NET_RSS_HASH_TYPE_TCPv6);
2566 		if (!is_disable)
2567 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6
2568 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_TCPv6 : 0);
2569 		break;
2570 	case UDP_V6_FLOW:
2571 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv6 | VIRTIO_NET_RSS_HASH_TYPE_UDPv6);
2572 		if (!is_disable)
2573 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6
2574 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv6 : 0);
2575 		break;
2576 	case IPV6_FLOW:
2577 		new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv6;
2578 		if (!is_disable)
2579 			new_hashtypes = VIRTIO_NET_RSS_HASH_TYPE_IPv6;
2580 		break;
2581 	default:
2582 		/* unsupported flow */
2583 		return false;
2584 	}
2585 
2586 	/* if unsupported hashtype was set */
2587 	if (new_hashtypes != (new_hashtypes & vi->rss_hash_types_supported))
2588 		return false;
2589 
2590 	if (new_hashtypes != vi->rss_hash_types_saved) {
2591 		vi->rss_hash_types_saved = new_hashtypes;
2592 		vi->ctrl->rss.hash_types = vi->rss_hash_types_saved;
2593 		if (vi->dev->features & NETIF_F_RXHASH)
2594 			return virtnet_commit_rss_command(vi);
2595 	}
2596 
2597 	return true;
2598 }
2599 
2600 static void virtnet_get_drvinfo(struct net_device *dev,
2601 				struct ethtool_drvinfo *info)
2602 {
2603 	struct virtnet_info *vi = netdev_priv(dev);
2604 	struct virtio_device *vdev = vi->vdev;
2605 
2606 	strscpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
2607 	strscpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
2608 	strscpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
2609 
2610 }
2611 
2612 /* TODO: Eliminate OOO packets during switching */
2613 static int virtnet_set_channels(struct net_device *dev,
2614 				struct ethtool_channels *channels)
2615 {
2616 	struct virtnet_info *vi = netdev_priv(dev);
2617 	u16 queue_pairs = channels->combined_count;
2618 	int err;
2619 
2620 	/* We don't support separate rx/tx channels.
2621 	 * We don't allow setting 'other' channels.
2622 	 */
2623 	if (channels->rx_count || channels->tx_count || channels->other_count)
2624 		return -EINVAL;
2625 
2626 	if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2627 		return -EINVAL;
2628 
2629 	/* For now we don't support modifying channels while XDP is loaded
2630 	 * also when XDP is loaded all RX queues have XDP programs so we only
2631 	 * need to check a single RX queue.
2632 	 */
2633 	if (vi->rq[0].xdp_prog)
2634 		return -EINVAL;
2635 
2636 	cpus_read_lock();
2637 	err = _virtnet_set_queues(vi, queue_pairs);
2638 	if (err) {
2639 		cpus_read_unlock();
2640 		goto err;
2641 	}
2642 	virtnet_set_affinity(vi);
2643 	cpus_read_unlock();
2644 
2645 	netif_set_real_num_tx_queues(dev, queue_pairs);
2646 	netif_set_real_num_rx_queues(dev, queue_pairs);
2647  err:
2648 	return err;
2649 }
2650 
2651 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2652 {
2653 	struct virtnet_info *vi = netdev_priv(dev);
2654 	unsigned int i, j;
2655 	u8 *p = data;
2656 
2657 	switch (stringset) {
2658 	case ETH_SS_STATS:
2659 		for (i = 0; i < vi->curr_queue_pairs; i++) {
2660 			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++)
2661 				ethtool_sprintf(&p, "rx_queue_%u_%s", i,
2662 						virtnet_rq_stats_desc[j].desc);
2663 		}
2664 
2665 		for (i = 0; i < vi->curr_queue_pairs; i++) {
2666 			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++)
2667 				ethtool_sprintf(&p, "tx_queue_%u_%s", i,
2668 						virtnet_sq_stats_desc[j].desc);
2669 		}
2670 		break;
2671 	}
2672 }
2673 
2674 static int virtnet_get_sset_count(struct net_device *dev, int sset)
2675 {
2676 	struct virtnet_info *vi = netdev_priv(dev);
2677 
2678 	switch (sset) {
2679 	case ETH_SS_STATS:
2680 		return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2681 					       VIRTNET_SQ_STATS_LEN);
2682 	default:
2683 		return -EOPNOTSUPP;
2684 	}
2685 }
2686 
2687 static void virtnet_get_ethtool_stats(struct net_device *dev,
2688 				      struct ethtool_stats *stats, u64 *data)
2689 {
2690 	struct virtnet_info *vi = netdev_priv(dev);
2691 	unsigned int idx = 0, start, i, j;
2692 	const u8 *stats_base;
2693 	size_t offset;
2694 
2695 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2696 		struct receive_queue *rq = &vi->rq[i];
2697 
2698 		stats_base = (u8 *)&rq->stats;
2699 		do {
2700 			start = u64_stats_fetch_begin(&rq->stats.syncp);
2701 			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2702 				offset = virtnet_rq_stats_desc[j].offset;
2703 				data[idx + j] = *(u64 *)(stats_base + offset);
2704 			}
2705 		} while (u64_stats_fetch_retry(&rq->stats.syncp, start));
2706 		idx += VIRTNET_RQ_STATS_LEN;
2707 	}
2708 
2709 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2710 		struct send_queue *sq = &vi->sq[i];
2711 
2712 		stats_base = (u8 *)&sq->stats;
2713 		do {
2714 			start = u64_stats_fetch_begin(&sq->stats.syncp);
2715 			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2716 				offset = virtnet_sq_stats_desc[j].offset;
2717 				data[idx + j] = *(u64 *)(stats_base + offset);
2718 			}
2719 		} while (u64_stats_fetch_retry(&sq->stats.syncp, start));
2720 		idx += VIRTNET_SQ_STATS_LEN;
2721 	}
2722 }
2723 
2724 static void virtnet_get_channels(struct net_device *dev,
2725 				 struct ethtool_channels *channels)
2726 {
2727 	struct virtnet_info *vi = netdev_priv(dev);
2728 
2729 	channels->combined_count = vi->curr_queue_pairs;
2730 	channels->max_combined = vi->max_queue_pairs;
2731 	channels->max_other = 0;
2732 	channels->rx_count = 0;
2733 	channels->tx_count = 0;
2734 	channels->other_count = 0;
2735 }
2736 
2737 static int virtnet_set_link_ksettings(struct net_device *dev,
2738 				      const struct ethtool_link_ksettings *cmd)
2739 {
2740 	struct virtnet_info *vi = netdev_priv(dev);
2741 
2742 	return ethtool_virtdev_set_link_ksettings(dev, cmd,
2743 						  &vi->speed, &vi->duplex);
2744 }
2745 
2746 static int virtnet_get_link_ksettings(struct net_device *dev,
2747 				      struct ethtool_link_ksettings *cmd)
2748 {
2749 	struct virtnet_info *vi = netdev_priv(dev);
2750 
2751 	cmd->base.speed = vi->speed;
2752 	cmd->base.duplex = vi->duplex;
2753 	cmd->base.port = PORT_OTHER;
2754 
2755 	return 0;
2756 }
2757 
2758 static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
2759 				       struct ethtool_coalesce *ec)
2760 {
2761 	struct scatterlist sgs_tx, sgs_rx;
2762 	struct virtio_net_ctrl_coal_tx coal_tx;
2763 	struct virtio_net_ctrl_coal_rx coal_rx;
2764 
2765 	coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
2766 	coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
2767 	sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx));
2768 
2769 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
2770 				  VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
2771 				  &sgs_tx))
2772 		return -EINVAL;
2773 
2774 	/* Save parameters */
2775 	vi->tx_usecs = ec->tx_coalesce_usecs;
2776 	vi->tx_max_packets = ec->tx_max_coalesced_frames;
2777 
2778 	coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
2779 	coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
2780 	sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx));
2781 
2782 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
2783 				  VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
2784 				  &sgs_rx))
2785 		return -EINVAL;
2786 
2787 	/* Save parameters */
2788 	vi->rx_usecs = ec->rx_coalesce_usecs;
2789 	vi->rx_max_packets = ec->rx_max_coalesced_frames;
2790 
2791 	return 0;
2792 }
2793 
2794 static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
2795 {
2796 	/* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL
2797 	 * feature is negotiated.
2798 	 */
2799 	if (ec->rx_coalesce_usecs || ec->tx_coalesce_usecs)
2800 		return -EOPNOTSUPP;
2801 
2802 	if (ec->tx_max_coalesced_frames > 1 ||
2803 	    ec->rx_max_coalesced_frames != 1)
2804 		return -EINVAL;
2805 
2806 	return 0;
2807 }
2808 
2809 static int virtnet_set_coalesce(struct net_device *dev,
2810 				struct ethtool_coalesce *ec,
2811 				struct kernel_ethtool_coalesce *kernel_coal,
2812 				struct netlink_ext_ack *extack)
2813 {
2814 	struct virtnet_info *vi = netdev_priv(dev);
2815 	int ret, i, napi_weight;
2816 	bool update_napi = false;
2817 
2818 	/* Can't change NAPI weight if the link is up */
2819 	napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2820 	if (napi_weight ^ vi->sq[0].napi.weight) {
2821 		if (dev->flags & IFF_UP)
2822 			return -EBUSY;
2823 		else
2824 			update_napi = true;
2825 	}
2826 
2827 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL))
2828 		ret = virtnet_send_notf_coal_cmds(vi, ec);
2829 	else
2830 		ret = virtnet_coal_params_supported(ec);
2831 
2832 	if (ret)
2833 		return ret;
2834 
2835 	if (update_napi) {
2836 		for (i = 0; i < vi->max_queue_pairs; i++)
2837 			vi->sq[i].napi.weight = napi_weight;
2838 	}
2839 
2840 	return ret;
2841 }
2842 
2843 static int virtnet_get_coalesce(struct net_device *dev,
2844 				struct ethtool_coalesce *ec,
2845 				struct kernel_ethtool_coalesce *kernel_coal,
2846 				struct netlink_ext_ack *extack)
2847 {
2848 	struct virtnet_info *vi = netdev_priv(dev);
2849 
2850 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
2851 		ec->rx_coalesce_usecs = vi->rx_usecs;
2852 		ec->tx_coalesce_usecs = vi->tx_usecs;
2853 		ec->tx_max_coalesced_frames = vi->tx_max_packets;
2854 		ec->rx_max_coalesced_frames = vi->rx_max_packets;
2855 	} else {
2856 		ec->rx_max_coalesced_frames = 1;
2857 
2858 		if (vi->sq[0].napi.weight)
2859 			ec->tx_max_coalesced_frames = 1;
2860 	}
2861 
2862 	return 0;
2863 }
2864 
2865 static void virtnet_init_settings(struct net_device *dev)
2866 {
2867 	struct virtnet_info *vi = netdev_priv(dev);
2868 
2869 	vi->speed = SPEED_UNKNOWN;
2870 	vi->duplex = DUPLEX_UNKNOWN;
2871 }
2872 
2873 static void virtnet_update_settings(struct virtnet_info *vi)
2874 {
2875 	u32 speed;
2876 	u8 duplex;
2877 
2878 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2879 		return;
2880 
2881 	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
2882 
2883 	if (ethtool_validate_speed(speed))
2884 		vi->speed = speed;
2885 
2886 	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
2887 
2888 	if (ethtool_validate_duplex(duplex))
2889 		vi->duplex = duplex;
2890 }
2891 
2892 static u32 virtnet_get_rxfh_key_size(struct net_device *dev)
2893 {
2894 	return ((struct virtnet_info *)netdev_priv(dev))->rss_key_size;
2895 }
2896 
2897 static u32 virtnet_get_rxfh_indir_size(struct net_device *dev)
2898 {
2899 	return ((struct virtnet_info *)netdev_priv(dev))->rss_indir_table_size;
2900 }
2901 
2902 static int virtnet_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, u8 *hfunc)
2903 {
2904 	struct virtnet_info *vi = netdev_priv(dev);
2905 	int i;
2906 
2907 	if (indir) {
2908 		for (i = 0; i < vi->rss_indir_table_size; ++i)
2909 			indir[i] = vi->ctrl->rss.indirection_table[i];
2910 	}
2911 
2912 	if (key)
2913 		memcpy(key, vi->ctrl->rss.key, vi->rss_key_size);
2914 
2915 	if (hfunc)
2916 		*hfunc = ETH_RSS_HASH_TOP;
2917 
2918 	return 0;
2919 }
2920 
2921 static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key, const u8 hfunc)
2922 {
2923 	struct virtnet_info *vi = netdev_priv(dev);
2924 	int i;
2925 
2926 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
2927 		return -EOPNOTSUPP;
2928 
2929 	if (indir) {
2930 		for (i = 0; i < vi->rss_indir_table_size; ++i)
2931 			vi->ctrl->rss.indirection_table[i] = indir[i];
2932 	}
2933 	if (key)
2934 		memcpy(vi->ctrl->rss.key, key, vi->rss_key_size);
2935 
2936 	virtnet_commit_rss_command(vi);
2937 
2938 	return 0;
2939 }
2940 
2941 static int virtnet_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info, u32 *rule_locs)
2942 {
2943 	struct virtnet_info *vi = netdev_priv(dev);
2944 	int rc = 0;
2945 
2946 	switch (info->cmd) {
2947 	case ETHTOOL_GRXRINGS:
2948 		info->data = vi->curr_queue_pairs;
2949 		break;
2950 	case ETHTOOL_GRXFH:
2951 		virtnet_get_hashflow(vi, info);
2952 		break;
2953 	default:
2954 		rc = -EOPNOTSUPP;
2955 	}
2956 
2957 	return rc;
2958 }
2959 
2960 static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info)
2961 {
2962 	struct virtnet_info *vi = netdev_priv(dev);
2963 	int rc = 0;
2964 
2965 	switch (info->cmd) {
2966 	case ETHTOOL_SRXFH:
2967 		if (!virtnet_set_hashflow(vi, info))
2968 			rc = -EINVAL;
2969 
2970 		break;
2971 	default:
2972 		rc = -EOPNOTSUPP;
2973 	}
2974 
2975 	return rc;
2976 }
2977 
2978 static const struct ethtool_ops virtnet_ethtool_ops = {
2979 	.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES |
2980 		ETHTOOL_COALESCE_USECS,
2981 	.get_drvinfo = virtnet_get_drvinfo,
2982 	.get_link = ethtool_op_get_link,
2983 	.get_ringparam = virtnet_get_ringparam,
2984 	.set_ringparam = virtnet_set_ringparam,
2985 	.get_strings = virtnet_get_strings,
2986 	.get_sset_count = virtnet_get_sset_count,
2987 	.get_ethtool_stats = virtnet_get_ethtool_stats,
2988 	.set_channels = virtnet_set_channels,
2989 	.get_channels = virtnet_get_channels,
2990 	.get_ts_info = ethtool_op_get_ts_info,
2991 	.get_link_ksettings = virtnet_get_link_ksettings,
2992 	.set_link_ksettings = virtnet_set_link_ksettings,
2993 	.set_coalesce = virtnet_set_coalesce,
2994 	.get_coalesce = virtnet_get_coalesce,
2995 	.get_rxfh_key_size = virtnet_get_rxfh_key_size,
2996 	.get_rxfh_indir_size = virtnet_get_rxfh_indir_size,
2997 	.get_rxfh = virtnet_get_rxfh,
2998 	.set_rxfh = virtnet_set_rxfh,
2999 	.get_rxnfc = virtnet_get_rxnfc,
3000 	.set_rxnfc = virtnet_set_rxnfc,
3001 };
3002 
3003 static void virtnet_freeze_down(struct virtio_device *vdev)
3004 {
3005 	struct virtnet_info *vi = vdev->priv;
3006 
3007 	/* Make sure no work handler is accessing the device */
3008 	flush_work(&vi->config_work);
3009 
3010 	netif_tx_lock_bh(vi->dev);
3011 	netif_device_detach(vi->dev);
3012 	netif_tx_unlock_bh(vi->dev);
3013 	if (netif_running(vi->dev))
3014 		virtnet_close(vi->dev);
3015 }
3016 
3017 static int init_vqs(struct virtnet_info *vi);
3018 
3019 static int virtnet_restore_up(struct virtio_device *vdev)
3020 {
3021 	struct virtnet_info *vi = vdev->priv;
3022 	int err;
3023 
3024 	err = init_vqs(vi);
3025 	if (err)
3026 		return err;
3027 
3028 	virtio_device_ready(vdev);
3029 
3030 	enable_delayed_refill(vi);
3031 
3032 	if (netif_running(vi->dev)) {
3033 		err = virtnet_open(vi->dev);
3034 		if (err)
3035 			return err;
3036 	}
3037 
3038 	netif_tx_lock_bh(vi->dev);
3039 	netif_device_attach(vi->dev);
3040 	netif_tx_unlock_bh(vi->dev);
3041 	return err;
3042 }
3043 
3044 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
3045 {
3046 	struct scatterlist sg;
3047 	vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
3048 
3049 	sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
3050 
3051 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
3052 				  VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
3053 		dev_warn(&vi->dev->dev, "Fail to set guest offload.\n");
3054 		return -EINVAL;
3055 	}
3056 
3057 	return 0;
3058 }
3059 
3060 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
3061 {
3062 	u64 offloads = 0;
3063 
3064 	if (!vi->guest_offloads)
3065 		return 0;
3066 
3067 	return virtnet_set_guest_offloads(vi, offloads);
3068 }
3069 
3070 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
3071 {
3072 	u64 offloads = vi->guest_offloads;
3073 
3074 	if (!vi->guest_offloads)
3075 		return 0;
3076 
3077 	return virtnet_set_guest_offloads(vi, offloads);
3078 }
3079 
3080 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
3081 			   struct netlink_ext_ack *extack)
3082 {
3083 	unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
3084 	struct virtnet_info *vi = netdev_priv(dev);
3085 	struct bpf_prog *old_prog;
3086 	u16 xdp_qp = 0, curr_qp;
3087 	int i, err;
3088 
3089 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
3090 	    && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3091 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3092 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
3093 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
3094 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM) ||
3095 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) ||
3096 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6))) {
3097 		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
3098 		return -EOPNOTSUPP;
3099 	}
3100 
3101 	if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
3102 		NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
3103 		return -EINVAL;
3104 	}
3105 
3106 	if (dev->mtu > max_sz) {
3107 		NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
3108 		netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
3109 		return -EINVAL;
3110 	}
3111 
3112 	curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
3113 	if (prog)
3114 		xdp_qp = nr_cpu_ids;
3115 
3116 	/* XDP requires extra queues for XDP_TX */
3117 	if (curr_qp + xdp_qp > vi->max_queue_pairs) {
3118 		netdev_warn_once(dev, "XDP request %i queues but max is %i. XDP_TX and XDP_REDIRECT will operate in a slower locked tx mode.\n",
3119 				 curr_qp + xdp_qp, vi->max_queue_pairs);
3120 		xdp_qp = 0;
3121 	}
3122 
3123 	old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
3124 	if (!prog && !old_prog)
3125 		return 0;
3126 
3127 	if (prog)
3128 		bpf_prog_add(prog, vi->max_queue_pairs - 1);
3129 
3130 	/* Make sure NAPI is not using any XDP TX queues for RX. */
3131 	if (netif_running(dev)) {
3132 		for (i = 0; i < vi->max_queue_pairs; i++) {
3133 			napi_disable(&vi->rq[i].napi);
3134 			virtnet_napi_tx_disable(&vi->sq[i].napi);
3135 		}
3136 	}
3137 
3138 	if (!prog) {
3139 		for (i = 0; i < vi->max_queue_pairs; i++) {
3140 			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
3141 			if (i == 0)
3142 				virtnet_restore_guest_offloads(vi);
3143 		}
3144 		synchronize_net();
3145 	}
3146 
3147 	err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
3148 	if (err)
3149 		goto err;
3150 	netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
3151 	vi->xdp_queue_pairs = xdp_qp;
3152 
3153 	if (prog) {
3154 		vi->xdp_enabled = true;
3155 		for (i = 0; i < vi->max_queue_pairs; i++) {
3156 			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
3157 			if (i == 0 && !old_prog)
3158 				virtnet_clear_guest_offloads(vi);
3159 		}
3160 	} else {
3161 		vi->xdp_enabled = false;
3162 	}
3163 
3164 	for (i = 0; i < vi->max_queue_pairs; i++) {
3165 		if (old_prog)
3166 			bpf_prog_put(old_prog);
3167 		if (netif_running(dev)) {
3168 			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
3169 			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
3170 					       &vi->sq[i].napi);
3171 		}
3172 	}
3173 
3174 	return 0;
3175 
3176 err:
3177 	if (!prog) {
3178 		virtnet_clear_guest_offloads(vi);
3179 		for (i = 0; i < vi->max_queue_pairs; i++)
3180 			rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
3181 	}
3182 
3183 	if (netif_running(dev)) {
3184 		for (i = 0; i < vi->max_queue_pairs; i++) {
3185 			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
3186 			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
3187 					       &vi->sq[i].napi);
3188 		}
3189 	}
3190 	if (prog)
3191 		bpf_prog_sub(prog, vi->max_queue_pairs - 1);
3192 	return err;
3193 }
3194 
3195 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
3196 {
3197 	switch (xdp->command) {
3198 	case XDP_SETUP_PROG:
3199 		return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
3200 	default:
3201 		return -EINVAL;
3202 	}
3203 }
3204 
3205 static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
3206 				      size_t len)
3207 {
3208 	struct virtnet_info *vi = netdev_priv(dev);
3209 	int ret;
3210 
3211 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
3212 		return -EOPNOTSUPP;
3213 
3214 	ret = snprintf(buf, len, "sby");
3215 	if (ret >= len)
3216 		return -EOPNOTSUPP;
3217 
3218 	return 0;
3219 }
3220 
3221 static int virtnet_set_features(struct net_device *dev,
3222 				netdev_features_t features)
3223 {
3224 	struct virtnet_info *vi = netdev_priv(dev);
3225 	u64 offloads;
3226 	int err;
3227 
3228 	if ((dev->features ^ features) & NETIF_F_GRO_HW) {
3229 		if (vi->xdp_enabled)
3230 			return -EBUSY;
3231 
3232 		if (features & NETIF_F_GRO_HW)
3233 			offloads = vi->guest_offloads_capable;
3234 		else
3235 			offloads = vi->guest_offloads_capable &
3236 				   ~GUEST_OFFLOAD_GRO_HW_MASK;
3237 
3238 		err = virtnet_set_guest_offloads(vi, offloads);
3239 		if (err)
3240 			return err;
3241 		vi->guest_offloads = offloads;
3242 	}
3243 
3244 	if ((dev->features ^ features) & NETIF_F_RXHASH) {
3245 		if (features & NETIF_F_RXHASH)
3246 			vi->ctrl->rss.hash_types = vi->rss_hash_types_saved;
3247 		else
3248 			vi->ctrl->rss.hash_types = VIRTIO_NET_HASH_REPORT_NONE;
3249 
3250 		if (!virtnet_commit_rss_command(vi))
3251 			return -EINVAL;
3252 	}
3253 
3254 	return 0;
3255 }
3256 
3257 static void virtnet_tx_timeout(struct net_device *dev, unsigned int txqueue)
3258 {
3259 	struct virtnet_info *priv = netdev_priv(dev);
3260 	struct send_queue *sq = &priv->sq[txqueue];
3261 	struct netdev_queue *txq = netdev_get_tx_queue(dev, txqueue);
3262 
3263 	u64_stats_update_begin(&sq->stats.syncp);
3264 	sq->stats.tx_timeouts++;
3265 	u64_stats_update_end(&sq->stats.syncp);
3266 
3267 	netdev_err(dev, "TX timeout on queue: %u, sq: %s, vq: 0x%x, name: %s, %u usecs ago\n",
3268 		   txqueue, sq->name, sq->vq->index, sq->vq->name,
3269 		   jiffies_to_usecs(jiffies - READ_ONCE(txq->trans_start)));
3270 }
3271 
3272 static const struct net_device_ops virtnet_netdev = {
3273 	.ndo_open            = virtnet_open,
3274 	.ndo_stop   	     = virtnet_close,
3275 	.ndo_start_xmit      = start_xmit,
3276 	.ndo_validate_addr   = eth_validate_addr,
3277 	.ndo_set_mac_address = virtnet_set_mac_address,
3278 	.ndo_set_rx_mode     = virtnet_set_rx_mode,
3279 	.ndo_get_stats64     = virtnet_stats,
3280 	.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
3281 	.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
3282 	.ndo_bpf		= virtnet_xdp,
3283 	.ndo_xdp_xmit		= virtnet_xdp_xmit,
3284 	.ndo_features_check	= passthru_features_check,
3285 	.ndo_get_phys_port_name	= virtnet_get_phys_port_name,
3286 	.ndo_set_features	= virtnet_set_features,
3287 	.ndo_tx_timeout		= virtnet_tx_timeout,
3288 };
3289 
3290 static void virtnet_config_changed_work(struct work_struct *work)
3291 {
3292 	struct virtnet_info *vi =
3293 		container_of(work, struct virtnet_info, config_work);
3294 	u16 v;
3295 
3296 	if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
3297 				 struct virtio_net_config, status, &v) < 0)
3298 		return;
3299 
3300 	if (v & VIRTIO_NET_S_ANNOUNCE) {
3301 		netdev_notify_peers(vi->dev);
3302 		virtnet_ack_link_announce(vi);
3303 	}
3304 
3305 	/* Ignore unknown (future) status bits */
3306 	v &= VIRTIO_NET_S_LINK_UP;
3307 
3308 	if (vi->status == v)
3309 		return;
3310 
3311 	vi->status = v;
3312 
3313 	if (vi->status & VIRTIO_NET_S_LINK_UP) {
3314 		virtnet_update_settings(vi);
3315 		netif_carrier_on(vi->dev);
3316 		netif_tx_wake_all_queues(vi->dev);
3317 	} else {
3318 		netif_carrier_off(vi->dev);
3319 		netif_tx_stop_all_queues(vi->dev);
3320 	}
3321 }
3322 
3323 static void virtnet_config_changed(struct virtio_device *vdev)
3324 {
3325 	struct virtnet_info *vi = vdev->priv;
3326 
3327 	schedule_work(&vi->config_work);
3328 }
3329 
3330 static void virtnet_free_queues(struct virtnet_info *vi)
3331 {
3332 	int i;
3333 
3334 	for (i = 0; i < vi->max_queue_pairs; i++) {
3335 		__netif_napi_del(&vi->rq[i].napi);
3336 		__netif_napi_del(&vi->sq[i].napi);
3337 	}
3338 
3339 	/* We called __netif_napi_del(),
3340 	 * we need to respect an RCU grace period before freeing vi->rq
3341 	 */
3342 	synchronize_net();
3343 
3344 	kfree(vi->rq);
3345 	kfree(vi->sq);
3346 	kfree(vi->ctrl);
3347 }
3348 
3349 static void _free_receive_bufs(struct virtnet_info *vi)
3350 {
3351 	struct bpf_prog *old_prog;
3352 	int i;
3353 
3354 	for (i = 0; i < vi->max_queue_pairs; i++) {
3355 		while (vi->rq[i].pages)
3356 			__free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
3357 
3358 		old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
3359 		RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
3360 		if (old_prog)
3361 			bpf_prog_put(old_prog);
3362 	}
3363 }
3364 
3365 static void free_receive_bufs(struct virtnet_info *vi)
3366 {
3367 	rtnl_lock();
3368 	_free_receive_bufs(vi);
3369 	rtnl_unlock();
3370 }
3371 
3372 static void free_receive_page_frags(struct virtnet_info *vi)
3373 {
3374 	int i;
3375 	for (i = 0; i < vi->max_queue_pairs; i++)
3376 		if (vi->rq[i].alloc_frag.page)
3377 			put_page(vi->rq[i].alloc_frag.page);
3378 }
3379 
3380 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
3381 {
3382 	if (!is_xdp_frame(buf))
3383 		dev_kfree_skb(buf);
3384 	else
3385 		xdp_return_frame(ptr_to_xdp(buf));
3386 }
3387 
3388 static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf)
3389 {
3390 	struct virtnet_info *vi = vq->vdev->priv;
3391 	int i = vq2rxq(vq);
3392 
3393 	if (vi->mergeable_rx_bufs)
3394 		put_page(virt_to_head_page(buf));
3395 	else if (vi->big_packets)
3396 		give_pages(&vi->rq[i], buf);
3397 	else
3398 		put_page(virt_to_head_page(buf));
3399 }
3400 
3401 static void free_unused_bufs(struct virtnet_info *vi)
3402 {
3403 	void *buf;
3404 	int i;
3405 
3406 	for (i = 0; i < vi->max_queue_pairs; i++) {
3407 		struct virtqueue *vq = vi->sq[i].vq;
3408 		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
3409 			virtnet_sq_free_unused_buf(vq, buf);
3410 	}
3411 
3412 	for (i = 0; i < vi->max_queue_pairs; i++) {
3413 		struct virtqueue *vq = vi->rq[i].vq;
3414 		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
3415 			virtnet_rq_free_unused_buf(vq, buf);
3416 	}
3417 }
3418 
3419 static void virtnet_del_vqs(struct virtnet_info *vi)
3420 {
3421 	struct virtio_device *vdev = vi->vdev;
3422 
3423 	virtnet_clean_affinity(vi);
3424 
3425 	vdev->config->del_vqs(vdev);
3426 
3427 	virtnet_free_queues(vi);
3428 }
3429 
3430 /* How large should a single buffer be so a queue full of these can fit at
3431  * least one full packet?
3432  * Logic below assumes the mergeable buffer header is used.
3433  */
3434 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
3435 {
3436 	const unsigned int hdr_len = vi->hdr_len;
3437 	unsigned int rq_size = virtqueue_get_vring_size(vq);
3438 	unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
3439 	unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
3440 	unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
3441 
3442 	return max(max(min_buf_len, hdr_len) - hdr_len,
3443 		   (unsigned int)GOOD_PACKET_LEN);
3444 }
3445 
3446 static int virtnet_find_vqs(struct virtnet_info *vi)
3447 {
3448 	vq_callback_t **callbacks;
3449 	struct virtqueue **vqs;
3450 	int ret = -ENOMEM;
3451 	int i, total_vqs;
3452 	const char **names;
3453 	bool *ctx;
3454 
3455 	/* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
3456 	 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
3457 	 * possible control vq.
3458 	 */
3459 	total_vqs = vi->max_queue_pairs * 2 +
3460 		    virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
3461 
3462 	/* Allocate space for find_vqs parameters */
3463 	vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
3464 	if (!vqs)
3465 		goto err_vq;
3466 	callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
3467 	if (!callbacks)
3468 		goto err_callback;
3469 	names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
3470 	if (!names)
3471 		goto err_names;
3472 	if (!vi->big_packets || vi->mergeable_rx_bufs) {
3473 		ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
3474 		if (!ctx)
3475 			goto err_ctx;
3476 	} else {
3477 		ctx = NULL;
3478 	}
3479 
3480 	/* Parameters for control virtqueue, if any */
3481 	if (vi->has_cvq) {
3482 		callbacks[total_vqs - 1] = NULL;
3483 		names[total_vqs - 1] = "control";
3484 	}
3485 
3486 	/* Allocate/initialize parameters for send/receive virtqueues */
3487 	for (i = 0; i < vi->max_queue_pairs; i++) {
3488 		callbacks[rxq2vq(i)] = skb_recv_done;
3489 		callbacks[txq2vq(i)] = skb_xmit_done;
3490 		sprintf(vi->rq[i].name, "input.%d", i);
3491 		sprintf(vi->sq[i].name, "output.%d", i);
3492 		names[rxq2vq(i)] = vi->rq[i].name;
3493 		names[txq2vq(i)] = vi->sq[i].name;
3494 		if (ctx)
3495 			ctx[rxq2vq(i)] = true;
3496 	}
3497 
3498 	ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
3499 				  names, ctx, NULL);
3500 	if (ret)
3501 		goto err_find;
3502 
3503 	if (vi->has_cvq) {
3504 		vi->cvq = vqs[total_vqs - 1];
3505 		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
3506 			vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
3507 	}
3508 
3509 	for (i = 0; i < vi->max_queue_pairs; i++) {
3510 		vi->rq[i].vq = vqs[rxq2vq(i)];
3511 		vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
3512 		vi->sq[i].vq = vqs[txq2vq(i)];
3513 	}
3514 
3515 	/* run here: ret == 0. */
3516 
3517 
3518 err_find:
3519 	kfree(ctx);
3520 err_ctx:
3521 	kfree(names);
3522 err_names:
3523 	kfree(callbacks);
3524 err_callback:
3525 	kfree(vqs);
3526 err_vq:
3527 	return ret;
3528 }
3529 
3530 static int virtnet_alloc_queues(struct virtnet_info *vi)
3531 {
3532 	int i;
3533 
3534 	if (vi->has_cvq) {
3535 		vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
3536 		if (!vi->ctrl)
3537 			goto err_ctrl;
3538 	} else {
3539 		vi->ctrl = NULL;
3540 	}
3541 	vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
3542 	if (!vi->sq)
3543 		goto err_sq;
3544 	vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
3545 	if (!vi->rq)
3546 		goto err_rq;
3547 
3548 	INIT_DELAYED_WORK(&vi->refill, refill_work);
3549 	for (i = 0; i < vi->max_queue_pairs; i++) {
3550 		vi->rq[i].pages = NULL;
3551 		netif_napi_add_weight(vi->dev, &vi->rq[i].napi, virtnet_poll,
3552 				      napi_weight);
3553 		netif_napi_add_tx_weight(vi->dev, &vi->sq[i].napi,
3554 					 virtnet_poll_tx,
3555 					 napi_tx ? napi_weight : 0);
3556 
3557 		sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
3558 		ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
3559 		sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
3560 
3561 		u64_stats_init(&vi->rq[i].stats.syncp);
3562 		u64_stats_init(&vi->sq[i].stats.syncp);
3563 	}
3564 
3565 	return 0;
3566 
3567 err_rq:
3568 	kfree(vi->sq);
3569 err_sq:
3570 	kfree(vi->ctrl);
3571 err_ctrl:
3572 	return -ENOMEM;
3573 }
3574 
3575 static int init_vqs(struct virtnet_info *vi)
3576 {
3577 	int ret;
3578 
3579 	/* Allocate send & receive queues */
3580 	ret = virtnet_alloc_queues(vi);
3581 	if (ret)
3582 		goto err;
3583 
3584 	ret = virtnet_find_vqs(vi);
3585 	if (ret)
3586 		goto err_free;
3587 
3588 	cpus_read_lock();
3589 	virtnet_set_affinity(vi);
3590 	cpus_read_unlock();
3591 
3592 	return 0;
3593 
3594 err_free:
3595 	virtnet_free_queues(vi);
3596 err:
3597 	return ret;
3598 }
3599 
3600 #ifdef CONFIG_SYSFS
3601 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
3602 		char *buf)
3603 {
3604 	struct virtnet_info *vi = netdev_priv(queue->dev);
3605 	unsigned int queue_index = get_netdev_rx_queue_index(queue);
3606 	unsigned int headroom = virtnet_get_headroom(vi);
3607 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
3608 	struct ewma_pkt_len *avg;
3609 
3610 	BUG_ON(queue_index >= vi->max_queue_pairs);
3611 	avg = &vi->rq[queue_index].mrg_avg_pkt_len;
3612 	return sprintf(buf, "%u\n",
3613 		       get_mergeable_buf_len(&vi->rq[queue_index], avg,
3614 				       SKB_DATA_ALIGN(headroom + tailroom)));
3615 }
3616 
3617 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
3618 	__ATTR_RO(mergeable_rx_buffer_size);
3619 
3620 static struct attribute *virtio_net_mrg_rx_attrs[] = {
3621 	&mergeable_rx_buffer_size_attribute.attr,
3622 	NULL
3623 };
3624 
3625 static const struct attribute_group virtio_net_mrg_rx_group = {
3626 	.name = "virtio_net",
3627 	.attrs = virtio_net_mrg_rx_attrs
3628 };
3629 #endif
3630 
3631 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
3632 				    unsigned int fbit,
3633 				    const char *fname, const char *dname)
3634 {
3635 	if (!virtio_has_feature(vdev, fbit))
3636 		return false;
3637 
3638 	dev_err(&vdev->dev, "device advertises feature %s but not %s",
3639 		fname, dname);
3640 
3641 	return true;
3642 }
3643 
3644 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)			\
3645 	virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
3646 
3647 static bool virtnet_validate_features(struct virtio_device *vdev)
3648 {
3649 	if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
3650 	    (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
3651 			     "VIRTIO_NET_F_CTRL_VQ") ||
3652 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
3653 			     "VIRTIO_NET_F_CTRL_VQ") ||
3654 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
3655 			     "VIRTIO_NET_F_CTRL_VQ") ||
3656 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
3657 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
3658 			     "VIRTIO_NET_F_CTRL_VQ") ||
3659 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS,
3660 			     "VIRTIO_NET_F_CTRL_VQ") ||
3661 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_HASH_REPORT,
3662 			     "VIRTIO_NET_F_CTRL_VQ") ||
3663 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_NOTF_COAL,
3664 			     "VIRTIO_NET_F_CTRL_VQ"))) {
3665 		return false;
3666 	}
3667 
3668 	return true;
3669 }
3670 
3671 #define MIN_MTU ETH_MIN_MTU
3672 #define MAX_MTU ETH_MAX_MTU
3673 
3674 static int virtnet_validate(struct virtio_device *vdev)
3675 {
3676 	if (!vdev->config->get) {
3677 		dev_err(&vdev->dev, "%s failure: config access disabled\n",
3678 			__func__);
3679 		return -EINVAL;
3680 	}
3681 
3682 	if (!virtnet_validate_features(vdev))
3683 		return -EINVAL;
3684 
3685 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3686 		int mtu = virtio_cread16(vdev,
3687 					 offsetof(struct virtio_net_config,
3688 						  mtu));
3689 		if (mtu < MIN_MTU)
3690 			__virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
3691 	}
3692 
3693 	return 0;
3694 }
3695 
3696 static bool virtnet_check_guest_gso(const struct virtnet_info *vi)
3697 {
3698 	return virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3699 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3700 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
3701 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
3702 		(virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) &&
3703 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6));
3704 }
3705 
3706 static void virtnet_set_big_packets(struct virtnet_info *vi, const int mtu)
3707 {
3708 	bool guest_gso = virtnet_check_guest_gso(vi);
3709 
3710 	/* If device can receive ANY guest GSO packets, regardless of mtu,
3711 	 * allocate packets of maximum size, otherwise limit it to only
3712 	 * mtu size worth only.
3713 	 */
3714 	if (mtu > ETH_DATA_LEN || guest_gso) {
3715 		vi->big_packets = true;
3716 		vi->big_packets_num_skbfrags = guest_gso ? MAX_SKB_FRAGS : DIV_ROUND_UP(mtu, PAGE_SIZE);
3717 	}
3718 }
3719 
3720 static int virtnet_probe(struct virtio_device *vdev)
3721 {
3722 	int i, err = -ENOMEM;
3723 	struct net_device *dev;
3724 	struct virtnet_info *vi;
3725 	u16 max_queue_pairs;
3726 	int mtu = 0;
3727 
3728 	/* Find if host supports multiqueue/rss virtio_net device */
3729 	max_queue_pairs = 1;
3730 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MQ) || virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
3731 		max_queue_pairs =
3732 		     virtio_cread16(vdev, offsetof(struct virtio_net_config, max_virtqueue_pairs));
3733 
3734 	/* We need at least 2 queue's */
3735 	if (max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
3736 	    max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
3737 	    !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3738 		max_queue_pairs = 1;
3739 
3740 	/* Allocate ourselves a network device with room for our info */
3741 	dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
3742 	if (!dev)
3743 		return -ENOMEM;
3744 
3745 	/* Set up network device as normal. */
3746 	dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE |
3747 			   IFF_TX_SKB_NO_LINEAR;
3748 	dev->netdev_ops = &virtnet_netdev;
3749 	dev->features = NETIF_F_HIGHDMA;
3750 
3751 	dev->ethtool_ops = &virtnet_ethtool_ops;
3752 	SET_NETDEV_DEV(dev, &vdev->dev);
3753 
3754 	/* Do we support "hardware" checksums? */
3755 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
3756 		/* This opens up the world of extra features. */
3757 		dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3758 		if (csum)
3759 			dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3760 
3761 		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
3762 			dev->hw_features |= NETIF_F_TSO
3763 				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
3764 		}
3765 		/* Individual feature bits: what can host handle? */
3766 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
3767 			dev->hw_features |= NETIF_F_TSO;
3768 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
3769 			dev->hw_features |= NETIF_F_TSO6;
3770 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
3771 			dev->hw_features |= NETIF_F_TSO_ECN;
3772 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_USO))
3773 			dev->hw_features |= NETIF_F_GSO_UDP_L4;
3774 
3775 		dev->features |= NETIF_F_GSO_ROBUST;
3776 
3777 		if (gso)
3778 			dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
3779 		/* (!csum && gso) case will be fixed by register_netdev() */
3780 	}
3781 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
3782 		dev->features |= NETIF_F_RXCSUM;
3783 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3784 	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
3785 		dev->features |= NETIF_F_GRO_HW;
3786 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
3787 		dev->hw_features |= NETIF_F_GRO_HW;
3788 
3789 	dev->vlan_features = dev->features;
3790 
3791 	/* MTU range: 68 - 65535 */
3792 	dev->min_mtu = MIN_MTU;
3793 	dev->max_mtu = MAX_MTU;
3794 
3795 	/* Configuration may specify what MAC to use.  Otherwise random. */
3796 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
3797 		u8 addr[ETH_ALEN];
3798 
3799 		virtio_cread_bytes(vdev,
3800 				   offsetof(struct virtio_net_config, mac),
3801 				   addr, ETH_ALEN);
3802 		eth_hw_addr_set(dev, addr);
3803 	} else {
3804 		eth_hw_addr_random(dev);
3805 	}
3806 
3807 	/* Set up our device-specific information */
3808 	vi = netdev_priv(dev);
3809 	vi->dev = dev;
3810 	vi->vdev = vdev;
3811 	vdev->priv = vi;
3812 
3813 	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
3814 	spin_lock_init(&vi->refill_lock);
3815 
3816 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
3817 		vi->mergeable_rx_bufs = true;
3818 
3819 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
3820 		vi->rx_usecs = 0;
3821 		vi->tx_usecs = 0;
3822 		vi->tx_max_packets = 0;
3823 		vi->rx_max_packets = 0;
3824 	}
3825 
3826 	if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
3827 		vi->has_rss_hash_report = true;
3828 
3829 	if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
3830 		vi->has_rss = true;
3831 
3832 	if (vi->has_rss || vi->has_rss_hash_report) {
3833 		vi->rss_indir_table_size =
3834 			virtio_cread16(vdev, offsetof(struct virtio_net_config,
3835 				rss_max_indirection_table_length));
3836 		vi->rss_key_size =
3837 			virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));
3838 
3839 		vi->rss_hash_types_supported =
3840 		    virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
3841 		vi->rss_hash_types_supported &=
3842 				~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX |
3843 				  VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
3844 				  VIRTIO_NET_RSS_HASH_TYPE_UDP_EX);
3845 
3846 		dev->hw_features |= NETIF_F_RXHASH;
3847 	}
3848 
3849 	if (vi->has_rss_hash_report)
3850 		vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash);
3851 	else if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
3852 		 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3853 		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
3854 	else
3855 		vi->hdr_len = sizeof(struct virtio_net_hdr);
3856 
3857 	if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
3858 	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3859 		vi->any_header_sg = true;
3860 
3861 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3862 		vi->has_cvq = true;
3863 
3864 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3865 		mtu = virtio_cread16(vdev,
3866 				     offsetof(struct virtio_net_config,
3867 					      mtu));
3868 		if (mtu < dev->min_mtu) {
3869 			/* Should never trigger: MTU was previously validated
3870 			 * in virtnet_validate.
3871 			 */
3872 			dev_err(&vdev->dev,
3873 				"device MTU appears to have changed it is now %d < %d",
3874 				mtu, dev->min_mtu);
3875 			err = -EINVAL;
3876 			goto free;
3877 		}
3878 
3879 		dev->mtu = mtu;
3880 		dev->max_mtu = mtu;
3881 	}
3882 
3883 	virtnet_set_big_packets(vi, mtu);
3884 
3885 	if (vi->any_header_sg)
3886 		dev->needed_headroom = vi->hdr_len;
3887 
3888 	/* Enable multiqueue by default */
3889 	if (num_online_cpus() >= max_queue_pairs)
3890 		vi->curr_queue_pairs = max_queue_pairs;
3891 	else
3892 		vi->curr_queue_pairs = num_online_cpus();
3893 	vi->max_queue_pairs = max_queue_pairs;
3894 
3895 	/* Allocate/initialize the rx/tx queues, and invoke find_vqs */
3896 	err = init_vqs(vi);
3897 	if (err)
3898 		goto free;
3899 
3900 #ifdef CONFIG_SYSFS
3901 	if (vi->mergeable_rx_bufs)
3902 		dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
3903 #endif
3904 	netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
3905 	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
3906 
3907 	virtnet_init_settings(dev);
3908 
3909 	if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3910 		vi->failover = net_failover_create(vi->dev);
3911 		if (IS_ERR(vi->failover)) {
3912 			err = PTR_ERR(vi->failover);
3913 			goto free_vqs;
3914 		}
3915 	}
3916 
3917 	if (vi->has_rss || vi->has_rss_hash_report)
3918 		virtnet_init_default_rss(vi);
3919 
3920 	/* serialize netdev register + virtio_device_ready() with ndo_open() */
3921 	rtnl_lock();
3922 
3923 	err = register_netdevice(dev);
3924 	if (err) {
3925 		pr_debug("virtio_net: registering device failed\n");
3926 		rtnl_unlock();
3927 		goto free_failover;
3928 	}
3929 
3930 	virtio_device_ready(vdev);
3931 
3932 	rtnl_unlock();
3933 
3934 	err = virtnet_cpu_notif_add(vi);
3935 	if (err) {
3936 		pr_debug("virtio_net: registering cpu notifier failed\n");
3937 		goto free_unregister_netdev;
3938 	}
3939 
3940 	virtnet_set_queues(vi, vi->curr_queue_pairs);
3941 
3942 	/* Assume link up if device can't report link status,
3943 	   otherwise get link status from config. */
3944 	netif_carrier_off(dev);
3945 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
3946 		schedule_work(&vi->config_work);
3947 	} else {
3948 		vi->status = VIRTIO_NET_S_LINK_UP;
3949 		virtnet_update_settings(vi);
3950 		netif_carrier_on(dev);
3951 	}
3952 
3953 	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
3954 		if (virtio_has_feature(vi->vdev, guest_offloads[i]))
3955 			set_bit(guest_offloads[i], &vi->guest_offloads);
3956 	vi->guest_offloads_capable = vi->guest_offloads;
3957 
3958 	pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
3959 		 dev->name, max_queue_pairs);
3960 
3961 	return 0;
3962 
3963 free_unregister_netdev:
3964 	unregister_netdev(dev);
3965 free_failover:
3966 	net_failover_destroy(vi->failover);
3967 free_vqs:
3968 	virtio_reset_device(vdev);
3969 	cancel_delayed_work_sync(&vi->refill);
3970 	free_receive_page_frags(vi);
3971 	virtnet_del_vqs(vi);
3972 free:
3973 	free_netdev(dev);
3974 	return err;
3975 }
3976 
3977 static void remove_vq_common(struct virtnet_info *vi)
3978 {
3979 	virtio_reset_device(vi->vdev);
3980 
3981 	/* Free unused buffers in both send and recv, if any. */
3982 	free_unused_bufs(vi);
3983 
3984 	free_receive_bufs(vi);
3985 
3986 	free_receive_page_frags(vi);
3987 
3988 	virtnet_del_vqs(vi);
3989 }
3990 
3991 static void virtnet_remove(struct virtio_device *vdev)
3992 {
3993 	struct virtnet_info *vi = vdev->priv;
3994 
3995 	virtnet_cpu_notif_remove(vi);
3996 
3997 	/* Make sure no work handler is accessing the device. */
3998 	flush_work(&vi->config_work);
3999 
4000 	unregister_netdev(vi->dev);
4001 
4002 	net_failover_destroy(vi->failover);
4003 
4004 	remove_vq_common(vi);
4005 
4006 	free_netdev(vi->dev);
4007 }
4008 
4009 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
4010 {
4011 	struct virtnet_info *vi = vdev->priv;
4012 
4013 	virtnet_cpu_notif_remove(vi);
4014 	virtnet_freeze_down(vdev);
4015 	remove_vq_common(vi);
4016 
4017 	return 0;
4018 }
4019 
4020 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
4021 {
4022 	struct virtnet_info *vi = vdev->priv;
4023 	int err;
4024 
4025 	err = virtnet_restore_up(vdev);
4026 	if (err)
4027 		return err;
4028 	virtnet_set_queues(vi, vi->curr_queue_pairs);
4029 
4030 	err = virtnet_cpu_notif_add(vi);
4031 	if (err) {
4032 		virtnet_freeze_down(vdev);
4033 		remove_vq_common(vi);
4034 		return err;
4035 	}
4036 
4037 	return 0;
4038 }
4039 
4040 static struct virtio_device_id id_table[] = {
4041 	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
4042 	{ 0 },
4043 };
4044 
4045 #define VIRTNET_FEATURES \
4046 	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
4047 	VIRTIO_NET_F_MAC, \
4048 	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
4049 	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
4050 	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
4051 	VIRTIO_NET_F_HOST_USO, VIRTIO_NET_F_GUEST_USO4, VIRTIO_NET_F_GUEST_USO6, \
4052 	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
4053 	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
4054 	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
4055 	VIRTIO_NET_F_CTRL_MAC_ADDR, \
4056 	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
4057 	VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \
4058 	VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_NOTF_COAL
4059 
4060 static unsigned int features[] = {
4061 	VIRTNET_FEATURES,
4062 };
4063 
4064 static unsigned int features_legacy[] = {
4065 	VIRTNET_FEATURES,
4066 	VIRTIO_NET_F_GSO,
4067 	VIRTIO_F_ANY_LAYOUT,
4068 };
4069 
4070 static struct virtio_driver virtio_net_driver = {
4071 	.feature_table = features,
4072 	.feature_table_size = ARRAY_SIZE(features),
4073 	.feature_table_legacy = features_legacy,
4074 	.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
4075 	.driver.name =	KBUILD_MODNAME,
4076 	.driver.owner =	THIS_MODULE,
4077 	.id_table =	id_table,
4078 	.validate =	virtnet_validate,
4079 	.probe =	virtnet_probe,
4080 	.remove =	virtnet_remove,
4081 	.config_changed = virtnet_config_changed,
4082 #ifdef CONFIG_PM_SLEEP
4083 	.freeze =	virtnet_freeze,
4084 	.restore =	virtnet_restore,
4085 #endif
4086 };
4087 
4088 static __init int virtio_net_driver_init(void)
4089 {
4090 	int ret;
4091 
4092 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
4093 				      virtnet_cpu_online,
4094 				      virtnet_cpu_down_prep);
4095 	if (ret < 0)
4096 		goto out;
4097 	virtionet_online = ret;
4098 	ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
4099 				      NULL, virtnet_cpu_dead);
4100 	if (ret)
4101 		goto err_dead;
4102 	ret = register_virtio_driver(&virtio_net_driver);
4103 	if (ret)
4104 		goto err_virtio;
4105 	return 0;
4106 err_virtio:
4107 	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
4108 err_dead:
4109 	cpuhp_remove_multi_state(virtionet_online);
4110 out:
4111 	return ret;
4112 }
4113 module_init(virtio_net_driver_init);
4114 
4115 static __exit void virtio_net_driver_exit(void)
4116 {
4117 	unregister_virtio_driver(&virtio_net_driver);
4118 	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
4119 	cpuhp_remove_multi_state(virtionet_online);
4120 }
4121 module_exit(virtio_net_driver_exit);
4122 
4123 MODULE_DEVICE_TABLE(virtio, id_table);
4124 MODULE_DESCRIPTION("Virtio network driver");
4125 MODULE_LICENSE("GPL");
4126